Common Misconceptions In the Hobby

[Peter Eichler]

Originally posted by aninjaatemyshoe
I'll reference the issue about the disease tonight when I get home. Don't have access to it right now.

Peter, the article you referenced (and the follow-up article) is quite nice in outlining how the natural reef environment is not as "stable" as we tend to think. The second article also impresses that it is important for corals in their natural environment to have environmental variation, but more so with seasonal variation as upposed to day-to-day variation. However, it doesn't even go into the physiological or even practicle issues that separate the natural environment from the aquarium environment. It had very little in terms of reef aquarium husbandry, just the assumption that variations in temp, salinity, so forth must directly translate to the best husbandry practices for us. The article talks about evolution and adaption over long periods of change, but again this is not something we are experiencing in our little "pieces of the ocean." It does meantion that environmental variations are important for sexual reproduction, but how many of us are striving for that? If anything, sexual reproduction is what we want to prevent because we are not prepared to handle the explosion of free floating nutrients. And even if we wanted this outcome, the environmental cues would require even more equipment and control of conditions than we tend to use in our aquariums. I don't think it prepares a very convincing case in regards to reef keeping.

Ok, but can you come up with a strong argument to support keeping aquariums lower in temperature with extremely consisten temperature conditions? The only reason those things are stressed now is because many years ago someone started spouting off about how stable reef conditions are so we should keep our aquariums stable. I agree that we need to adjust some of our procedures to better suit home aquaria. However, the old suggestions of keeping temps below 80 and always keeping them stable holds little weight, even when you consider the differences between the reef and out aquariums. Lastly, we should be striving for spawning events. If we can find a way to replicate them it would be a great advance in this hobby. Until then spawning events are not so common in aquariums that maintain higher water temps to warrant not trying better to replicate natural conditions.

[aninjaatemyshoe]

Ok, my references all come from the Reef Aquarium V. 3 (Delbeek and Sprung), which is a great in-depth source. For the purposes of trying to keep this somewhat brief, I have skipped some things and tried to hit the major points.

I didn't notice at first, but it actually references the Shimek article:

(pg 134) - "Following the logic that Mother Nature knows best Shimek (1997, 2000) proposes that a temperature in that range [82-87 degrees Fahrenheit] is best for captive reefs. Our experience in a closed aquarium has demonstrated that the temperature in a closed aquarium should not be maintained near the natural thermal tolerances of corals; on the contrary, it should be maintained significantly lower. The reason for this is due to more than one effect... Our recommendation to maintain reef aquariums at cooler temperatures assumes that the goal is to maintain a diverse population of corals, other reef life and fish in a stable environment that promotes their long-term health with minimal risk of disease or accidental suffocation...High temperature in combination with longer day lengths and salinity changes trigger spawning in the natural environment and in aquariums... coral, anemone, tridacnid clam, [etc] which commonly occurs in the warmest months can be a major problem for closed system aquariums. The release of gametes into the water rapidly consumes oxygen, poisons the tank, clogs the filters, or causes the protein skimmer foam to collapse... [this] is not something that can can be safely managed in a typical closed system aquarium... [however] maintaining a constant, lower temperature in aquariums cannot be considered the definitive means of preventing mass spawning."

(pg 135)
"The principle difference regarding temperature between the natural environment and the aquarium has to do with oxygen availability... the increase in water temperature causes a much more significant issue, the increase in metabolism, and consequently respiration, of the life in the aquarium. The increase in respiration also rises sharply as the thermal tolerance of an animal is approached. This increase in metabolism associated with increase in temperature happens in the natural environment as well, but there it is not as critical as in aquariums because of the ratio of water volume to mass of life."

(pg 136)
"Research on coral bleaching has repeatedly shown that when temperatures exceed the natural temperature extremes by as little as 1 or 2 degrees Celsius, bleaching and subsequent death in corals can occur... Fernando Nosratpour, assistant Aquarium curator at the Birch Aquarium at Scripps in San Diego, reports that the temperature in his Indo-Pacific reef tank ranges from 77 to 83 degrees but is only at 83 for one week in the summer. However, if the temperature rises to 84/85 degrees for ten days or more then signs of bleaching began to appear in the corals."

(pg 137)
"In our experience, the incidence of rapid tissue necrosis (RTN) and other bacterial diseases that affect corals also increases with increasing temperature. Recent scientific research on coral disease supports our aquarium observations... Vibrio coralliilyticus, becomes virulent at just 3 degrees above normal water temperatures and causes complete tissue loss in Pocillopora damicornis. Ben-Haim and Rosenberg (2002) showed that when corals were inoculated with the bacterium at 68 and 77 degrees, no disease appeared after 20 days, but 100% of the tested fragments showed disease and died at 80.6 and 84.2 degrees after just 16 days... [another case] found that when the temperature reached 82.6 degrees an outbreak of Dark Spots Disease occurred. [It was] concluded that conditions within the aquarium might have contributed to this outbreak since the daily temperature fluctuated more than 4.5 degrees and may have created a more stressful situation."

(pg 139) "The bottom line is that an aquarium environment is not the same as the ocean environment. Light fields, light intensity, water chemistry, volume, and water motion in aquariums are all significantly different from those in the ocean."

The book goes on in other sections to talk about other reasons why mid-high 70s is the ideal, but I think I've cited enough. Point is that they provide far more compelling evidence to support their claims than the Shimek article as they are actually talking about experiences within reef aquariums and not just looking at what occurs in the ocean.

[Peter Eichler]

Originally posted by aninjaatemyshoe
Ok, my references all come from the Reef Aquarium V. 3 (Delbeek and Sprung), which is a great in-depth source. For the purposes of trying to keep this somewhat brief, I have skipped some things and tried to hit the major points.

I didn't notice at first, but it actually references the Shimek article:

(pg 134) - "Following the logic that Mother Nature knows best Shimek (1997, 2000) proposes that a temperature in that range [82-87 degrees Fahrenheit] is best for captive reefs. Our experience in a closed aquarium has demonstrated that the temperature in a closed aquarium should not be maintained near the natural thermal tolerances of corals; on the contrary, it should be maintained significantly lower. The reason for this is due to more than one effect... Our recommendation to maintain reef aquariums at cooler temperatures assumes that the goal is to maintain a diverse population of corals, other reef life and fish in a stable environment that promotes their long-term health with minimal risk of disease or accidental suffocation...High temperature in combination with longer day lengths and salinity changes trigger spawning in the natural environment and in aquariums... coral, anemone, tridacnid clam, [etc] which commonly occurs in the warmest months can be a major problem for closed system aquariums. The release of gametes into the water rapidly consumes oxygen, poisons the tank, clogs the filters, or causes the protein skimmer foam to collapse... [this] is not something that can can be safely managed in a typical closed system aquarium... [however] maintaining a constant, lower temperature in aquariums cannot be considered the definitive means of preventing mass spawning."

(pg 135)
"The principle difference regarding temperature between the natural environment and the aquarium has to do with oxygen availability... the increase in water temperature causes a much more significant issue, the increase in metabolism, and consequently respiration, of the life in the aquarium. The increase in respiration also rises sharply as the thermal tolerance of an animal is approached. This increase in metabolism associated with increase in temperature happens in the natural environment as well, but there it is not as critical as in aquariums because of the ratio of water volume to mass of life."

(pg 136)
"Research on coral bleaching has repeatedly shown that when temperatures exceed the natural temperature extremes by as little as 1 or 2 degrees Celsius, bleaching and subsequent death in corals can occur... Fernando Nosratpour, assistant Aquarium curator at the Birch Aquarium at Scripps in San Diego, reports that the temperature in his Indo-Pacific reef tank ranges from 77 to 83 degrees but is only at 83 for one week in the summer. However, if the temperature rises to 84/85 degrees for ten days or more then signs of bleaching began to appear in the corals."

(pg 137)
"In our experience, the incidence of rapid tissue necrosis (RTN) and other bacterial diseases that affect corals also increases with increasing temperature. Recent scientific research on coral disease supports our aquarium observations... Vibrio coralliilyticus, becomes virulent at just 3 degrees above normal water temperatures and causes complete tissue loss in Pocillopora damicornis. Ben-Haim and Rosenberg (2002) showed that when corals were inoculated with the bacterium at 68 and 77 degrees, no disease appeared after 20 days, but 100% of the tested fragments showed disease and died at 80.6 and 84.2 degrees after just 16 days... [another case] found that when the temperature reached 82.6 degrees an outbreak of Dark Spots Disease occurred. [It was] concluded that conditions within the aquarium might have contributed to this outbreak since the daily temperature fluctuated more than 4.5 degrees and may have created a more stressful situation."

(pg 139) "The bottom line is that an aquarium environment is not the same as the ocean environment. Light fields, light intensity, water chemistry, volume, and water motion in aquariums are all significantly different from those in the ocean."

The book goes on in other sections to talk about other reasons why mid-high 70s is the ideal, but I think I've cited enough. Point is that they provide far more compelling evidence to support their claims than the Shimek article as they are actually talking about experiences within reef aquariums and not just looking at what occurs in the ocean.

Sprung is a good aquarist and wrote some good books but he's been wrong many times before and he'll be wrong again. He's a hobbyist just like many of us and he has been known to follow common beliefs and trends just like many of us. When I want a supplement I don't need I'll trust Sprung. Other than that I'll put a little more faith in natural conditions and personal observations. For years I was made deathly affraid of temps breaking the 80 degree mark because of Sprung, and it was complete and total nonsense.

[dougie]

[QUOTE]Originally posted by ManotheSea
I now use fresh from the ocean live sand.

do you collect this sand yourself from a beach? or
do you buy the live sand?

Ive been curious about using sand from my local beaches for ages, also snails from the tide pools as a clean up crew.

Never had the guts to try in fear something will go bad.

Whats your thoughts?

[fishdoc11]

Originally posted by Peter Eichler
15.) Higher Kelvin bulbs such as those in the 14k-20k range will cause corals to "color up".

All the scientific research done in this area suggests that Kelvin has no effect on the bright coloration of corals. When it comes to lighting, intesity is the deciding factor on what color you corals are/will be. If you observe your corals getting more colorful after switching to a higher Kelvin bulb it's a result of the change in intesity and the perception of color that comes along with the higher Kelvin and greater blue spectrum.

Conclusion: This one is pretty harmless, but it's one of those beliefs that is perpetuated over and over again on this forum. There are other factors that will help determine coral coloration but all research suggests that the Kelvin of the light source is not one of them.

Scientific research or not, and we all know sometimes even that isn't correct, this not true. At least to the extent that if you took a frag of the same coral and placed it in equal systems with the only difference being one was lit by a 20K Radium and one a 10K Ushio often times the coloration will be very different (out of the tank). "Better" is in the eye of the beholder but they can definately be very different.

Nice thread....good info mostly

Chris

[greenbean36191]

The principle difference regarding temperature between the natural environment and the aquarium has to do with oxygen availability... the increase in water temperature causes a much more significant issue, the increase in metabolism, and consequently respiration, of the life in the aquarium. The increase in respiration also rises sharply as the thermal tolerance of an animal is approached. This increase in metabolism associated with increase in temperature happens in the natural environment as well, but there it is not as critical as in aquariums because of the ratio of water volume to mass of life.

The magnitude of this problem is very exaggerated. Assuming no thermal stress, (which there shouldn't be over this normal range) going from 78-86 increases metabolism by about 20% and reduces oxygen saturation by about 7%. That equates to about a .5 mg/L loss of oxygen and the actual DO levels will still be around 2 and a half times the safe limit. You're way overstocked or have major aeration issues if temperature is having a noticeable affect on your inhabitants. Regardless of what temperature you run, it's just a bandaid.

The spike you get when you near the tolerance shouldn't be an issue because that spike doesn't occur in most species until 88-92, assuming their natural tolerance hasn't been reduced by low or stable temperatures.

Research on coral bleaching has repeatedly shown that when temperatures exceed the natural temperature extremes by as little as 1 or 2 degrees Celsius, bleaching and subsequent death in corals can occur... Fernando Nosratpour, assistant Aquarium curator at the Birch Aquarium at Scripps in San Diego, reports that the temperature in his Indo-Pacific reef tank ranges from 77 to 83 degrees but is only at 83 for one week in the summer. However, if the temperature rises to 84/85 degrees for ten days or more then signs of bleaching began to appear in the corals.

The first part of this statement is indisputable. The second part, IMO only reinforces what Peter has been saying since the first post. You have to ask yourself why these corals are bleaching at temperatures they would regularly see on the reefs in nature and have been shown to be around the range of their growth optima in the lab? If it's something inherent about a captive system then why do so many people in the hobby regularly see those temperatures without ill effect? My tank runs at 86 almost every day during the summer, and sometimes up to 88 or even 90 for a few days, yet bleaching isn't a problem. Dr. Brian Helmuth's work has confirmed that if you keep corals at lower or more stable temps they show extreme stress, while other corals from more natural regimes keep metabolizing normally, even under unnaturally high temps.

[greenbean36191]

Agreed with this one. I've never been convinced that our hobby is a real threat to the reefs. It makes some impact, but when you consider what climate change and polution are doing, it is like a scraped knee on a cancer patient. I'm certainly not advocating unethical collection, and I think aquaculture is best, but there needs to be some perspective here. Our focus should be on projects to decrease oceanic pollution and promote sustainable methods of fishing/collection from the sea.

This actually wasn't my point at all. Collection for the hobby is a real threat to the reefs, regardless of how it compares to other factors. My point is that many people in the hobby are under the mistaken impression that stopping the collection of wild fish and corals for the hobby will significantly reduce the amount of animals taken from the reef. It's just not true. The collectors still need to make money and most don't have many other economic alternatives besides harvesting from the reef. If they can no longer sell to us they will just sell to the next highest bidder. There is no shortage of demand for corals and fish from other industries.

Trading frags does little to reduce the amount of animals being taken from the reef and stymies the growth of in situ aquaculture that really could provide economic alternatives for the collectors.

[capn_hylinur]

I apologize for not knowing this thread was alreadystarted on this topic --I've tried to research it with no luck.

I for one, am so greatful to the dedicated moderators on this form that with their leadership and the input of many others hobbyists like mysef, for clearing up or explain alot of misconceptions that I have learned along the way.

I'll state a few :

Biggest misconception was that marine fish don't adapt or have a hard time adapting to change.
The "corrected" statement is that they can adapt to change providing it is within the low and high range of real reef conditions.

Another misconception was based around "Ich" I was totally in the dark about its life cycle and the subsequent treatment to use.
Once I understood the life cycle it made more sense to use a quarantine tank and hyposalinate it.

Another misconception was based around the methods and reasons for treating cyano

And finally for now---the misconception that algae was encouraged by light and reducting light would irradicate it.
This is of course false--the number one factor for increasing the growth of algae is nutrients. finding and cutting down the sources of nutrients will go along way for curbing algae rather then reducing the light.

Way to go Peter----this will be an awesome and valuable thread as it takes off
Scott

[aninjaatemyshoe]

"Sprung is a good aquarist and wrote some good books but he's been wrong many times before and he'll be wrong again. He's a hobbyist just like many of us and he has been known to follow common beliefs and trends just like many of us. When I want a supplement I don't need I'll trust Sprung. Other than that I'll put a little more faith in natural conditions and personal observations. For years I was made deathly affraid of temps breaking the 80 degree mark because of Sprung, and it was complete and total nonsense."

I don't know what you're talking about regarding the unneeded supplements, I've read through his whole book and never once read something recommending adding supplements beyond the typical calcium, alkalinity, and magnesium. He talks about other trace elements, but doesn't say you "need" to add them.

I'm going to try to make my point clear regarding mid to high 70 degree temperature and stability: It is a GOOD thing. I'm not saying, nor does Sprung's book say, that it is prescriptive for maintaining a healthy reef aquarium. It is simple a great way to further ensure the health of our inhabitants. Why in hell would we be recommending that people don't care about the temperature swings or maintaining a tolerable temperature? Sure, people who have been in the hobby for some time and are quite good at all other elements may need not worry so much, but to the new guys this is bad advice. You talk about your experiences as if they apply to everyone. Tell me one story about someone who maintained the temperature as stated above and had corals suffer for it? I have heard plenty of stories that have pointed to thermal stress causing big problems in their tanks.


"The magnitude of this problem is very exaggerated. Assuming no thermal stress, (which there shouldn't be over this normal range) going from 78-86 increases metabolism by about 20% and reduces oxygen saturation by about 7%. That equates to about a .5 mg/L loss of oxygen and the actual DO levels will still be around 2 and a half times the safe limit. You're way overstocked or have major aeration issues if temperature is having a noticeable affect on your inhabitants. Regardless of what temperature you run, it's just a bandaid."

It is true that the oxygen depletion from higher temps will not be a problem for an aquarium in which there is rather good oxygenation to start with. Problem is that I don't think that is as common as you are assuming. During the night, without the aid of photosynthesis, the oxygen levels can already decrease. Then add on top of that the depleted oxygen from higher temps and you're reaching levels that can put too much stress on our livestock. Certainly, many things such as a reverse daylight refugium, a high turn-over rate on a good protein skimmer, and use of a sump will help alleviate these issues. But as I stated before, unfortunately plenty of aquarists are not providing sufficient oxygenation to make up for such depletion. Sure, we should encourage that they make up for that, but why not also encourage that they keep the temps in a range that will not worsen the problem?

"The spike you get when you near the tolerance shouldn't be an issue because that spike doesn't occur in most species until 88-92, assuming their natural tolerance hasn't been reduced by low or stable temperatures."

So what, are you suggesting that we try and impose hormesis on our livestock by varying the temp and putting them in higher temperature water? How should this practically be acheived? It should be done in a way similar to how it occurs in nature (according to the argument you guys are putting forth). Just simply allowing the temp in our tanks to sway back and forth is not replicating how it occurs in nature, sorry I don't buy it.


"The first part of this statement is indisputable. The second part, IMO only reinforces what Peter has been saying since the first post. You have to ask yourself why these corals are bleaching at temperatures they would regularly see on the reefs in nature and have been shown to be around the range of their growth optima in the lab? If it's something inherent about a captive system then why do so many people in the hobby regularly see those temperatures without ill effect? My tank runs at 86 almost every day during the summer, and sometimes up to 88 or even 90 for a few days, yet bleaching isn't a problem. Dr. Brian Helmuth's work has confirmed that if you keep corals at lower or more stable temps they show extreme stress, while other corals from more natural regimes keep metabolizing normally, even under unnaturally high temps."

Corals do show adaptability to the ranges in which you place them. Once they adapt to that situation, changing the conditions drastically has an obviously negative affect. You can keep them in higher temperature tanks so long as you willing to accept some of the other issues that come along with that. Among the ones listed above, the ones that stick out are the oxygen depletion and the increase in disease activity. Spawning is potentially another issue, but as stated above you don't absolutely avoid it by maintaining lower temperatures.

In the end, it really comes down to what you are going to recommend we should be doing in regards to temperature in our tanks. Telling people they should not care about temp swings is not helping anything. There is no denying that temp swings causes some stress, and in tanks where there already is a good amount of stress from other factors, this can build up to issues such as disease and coral bleaching. As far as what temperature to strive for, I've seen the evidence supporting mid-high 70s and have not seen anything convincing saying low-mid 80s. The idea that keeping a lower temp makes corals vulnerable to higher temps, while valid, is not an adequate reason. After all, the converse could be said about maintaining higher temps; that they make the corals vulnerable to lower temps. Then there is the point made about optimum growth rates, but this is something that applies to certain specific corals in controlled laboratory situations. This is not a real analog to our aquariums, which are not quite so controlled in other factors and contain corals of many different varieties from many different regions and potentially even different oceans.

[Peter Eichler]

Originally posted by aninjaatemyshoe
"Sprung is a good aquarist and wrote some good books but he's been wrong many times before and he'll be wrong again. He's a hobbyist just like many of us and he has been known to follow common beliefs and trends just like many of us. When I want a supplement I don't need I'll trust Sprung. Other than that I'll put a little more faith in natural conditions and personal observations. For years I was made deathly affraid of temps breaking the 80 degree mark because of Sprung, and it was complete and total nonsense."

I don't know what you're talking about regarding the unneeded supplements, I've read through his whole book and never once read something recommending adding supplements beyond the typical calcium, alkalinity, and magnesium. He talks about other trace elements, but doesn't say you "need" to add them.

I'm going to try to make my point clear regarding mid to high 70 degree temperature and stability: It is a GOOD thing. I'm not saying, nor does Sprung's book say, that it is prescriptive for maintaining a healthy reef aquarium. It is simple a great way to further ensure the health of our inhabitants. Why in hell would we be recommending that people don't care about the temperature swings or maintaining a tolerable temperature? Sure, people who have been in the hobby for some time and are quite good at all other elements may need not worry so much, but to the new guys this is bad advice. You talk about your experiences as if they apply to everyone. Tell me one story about someone who maintained the temperature as stated above and had corals suffer for it? I have heard plenty of stories that have pointed to thermal stress causing big problems in their tanks.


"The magnitude of this problem is very exaggerated. Assuming no thermal stress, (which there shouldn't be over this normal range) going from 78-86 increases metabolism by about 20% and reduces oxygen saturation by about 7%. That equates to about a .5 mg/L loss of oxygen and the actual DO levels will still be around 2 and a half times the safe limit. You're way overstocked or have major aeration issues if temperature is having a noticeable affect on your inhabitants. Regardless of what temperature you run, it's just a bandaid."

It is true that the oxygen depletion from higher temps will not be a problem for an aquarium in which there is rather good oxygenation to start with. Problem is that I don't think that is as common as you are assuming. During the night, without the aid of photosynthesis, the oxygen levels can already decrease. Then add on top of that the depleted oxygen from higher temps and you're reaching levels that can put too much stress on our livestock. Certainly, many things such as a reverse daylight refugium, a high turn-over rate on a good protein skimmer, and use of a sump will help alleviate these issues. But as I stated before, unfortunately plenty of aquarists are not providing sufficient oxygenation to make up for such depletion. Sure, we should encourage that they make up for that, but why not also encourage that they keep the temps in a range that will not worsen the problem?

"The spike you get when you near the tolerance shouldn't be an issue because that spike doesn't occur in most species until 88-92, assuming their natural tolerance hasn't been reduced by low or stable temperatures."

So what, are you suggesting that we try and impose hormesis on our livestock by varying the temp and putting them in higher temperature water? How should this practically be acheived? It should be done in a way similar to how it occurs in nature (according to the argument you guys are putting forth). Just simply allowing the temp in our tanks to sway back and forth is not replicating how it occurs in nature, sorry I don't buy it.


"The first part of this statement is indisputable. The second part, IMO only reinforces what Peter has been saying since the first post. You have to ask yourself why these corals are bleaching at temperatures they would regularly see on the reefs in nature and have been shown to be around the range of their growth optima in the lab? If it's something inherent about a captive system then why do so many people in the hobby regularly see those temperatures without ill effect? My tank runs at 86 almost every day during the summer, and sometimes up to 88 or even 90 for a few days, yet bleaching isn't a problem. Dr. Brian Helmuth's work has confirmed that if you keep corals at lower or more stable temps they show extreme stress, while other corals from more natural regimes keep metabolizing normally, even under unnaturally high temps."

Corals do show adaptability to the ranges in which you place them. Once they adapt to that situation, changing the conditions drastically has an obviously negative affect. You can keep them in higher temperature tanks so long as you willing to accept some of the other issues that come along with that. Among the ones listed above, the ones that stick out are the oxygen depletion and the increase in disease activity. Spawning is potentially another issue, but as stated above you don't absolutely avoid it by maintaining lower temperatures.

In the end, it really comes down to what you are going to recommend we should be doing in regards to temperature in our tanks. Telling people they should not care about temp swings is not helping anything. There is no denying that temp swings causes some stress, and in tanks where there already is a good amount of stress from other factors, this can build up to issues such as disease and coral bleaching. As far as what temperature to strive for, I've seen the evidence supporting mid-high 70s and have not seen anything convincing saying low-mid 80s. The idea that keeping a lower temp makes corals vulnerable to higher temps, while valid, is not an adequate reason. After all, the converse could be said about maintaining higher temps; that they make the corals vulnerable to lower temps. Then there is the point made about optimum growth rates, but this is something that applies to certain specific corals in controlled laboratory situations. This is not a real analog to our aquariums, which are not quite so controlled in other factors and contain corals of many different varieties from many different regions and potentially even different oceans.

We've really gone overboard with this part of the list and you still seem to insist on saying we're recommending something that we're not.

1.) Julian Sprung is one of those authors that has perpetuated the need to keep temperatures below 80 degrees and incredibly stable. It's an absolute fact that there are many people that have have spectacular aquariums that run over 80 degrees and have fluctuations on warm days and when lights are on throughout the day with no apparent negatives. The unneeded supplement comment is in reference to most of the supplements his company offers. I'd be interested to see what Julian has to say on this topic now

2.) If your oxygen levels are low at 77 degrees they will still be low at 87 degrees. Sure, you could create some slippery slope where oxygen levels are barely sufficient in a tank at a lower temperature and they could become slightly dangerous if the temperature raises, but the chance of that happening is very small. Also, with the event of enexpensive and efficient pumps and skimmers being widely in the hobby now I don't see many people having low oxygen levels in their system.

3.) Greenbean nor I are advocating someone strive for wild temperature fluctuations. Simply put, if your temperatures are going up a few degrees slowly through the course of a day when your metal halide lights go on it's nothing to worry about. Not only that, it's quite natural and very similar to what happens on a reef.

4.) If the fact that temperatures in the 80's are completely natural and that temperature swings occur multiple times a day on a natural reef isn't convincing to you then we're just going to have to agree to disagree. You should also consider the many very successful reef aquariums maintaining temps above 80 and having temp swings as not convincing.

[eskymick]

Originally posted by Peter Eichler
What the heck is a gander anyhow?

Someone from Michigan !!

Sorry ... couldn't resist.

[greenbean36191]

Why in hell would we be recommending that people don't care about the temperature swings or maintaining a tolerable temperature? Sure, people who have been in the hobby for some time and are quite good at all other elements may need not worry so much, but to the new guys this is bad advice.

Absolutely not. With all of the other things new hobbyists worry about why in the world should we have them chasing a goal that can only hurt their animals? Stability is not a natural condition for reef animals. There is no evidence that it reduces stress, and it only makes the animals more sensitive to newbie mistakes.

It is true that the oxygen depletion from higher temps will not be a problem for an aquarium in which there is rather good oxygenation to start with. Problem is that I don't think that is as common as you are assuming.

Eric Borneman did some tests on several aquaria and found most to be around 80%-90% of saturation with the lights on and falling to about 75% after 2 hours with lights off.

So what, are you suggesting that we try and impose hormesis on our livestock by varying the temp and putting them in higher temperature water? How should this practically be acheived? It should be done in a way similar to how it occurs in nature (according to the argument you guys are putting forth). Just simply allowing the temp in our tanks to sway back and forth is not replicating how it occurs in nature, sorry I don't buy it.

I made that comment in regards to Sprung and Delbeek's mention that as you near an animal's limits they will use more oxygen. It's essentially a non-issue since even in the low to mid 80's your corals aren't near their limits unless you've acclimatized them to unnaturally cool temperatures. It had nothing to do with a recommendation of what temperature to run your tank at.

No, just allowing the temp in our tanks to swing back and forth doesn't replicate nature. It's much slower than what happens in the wild. When I was working in the Bahamas one of the guys at the research station had temp loggers placed all over the reef, (which was recovering, not declining). There was a 5-8 degree variation everyday and at least once that I saw there was a 6 degree change within 15 minutes, which was the periodicity of his readings. When I was doing my work nearby I saw too many 3 and 4 degree changes to count and at least one almost instant 6 degree change, which you can REALLY feel when it happens.

Here are some current graphs from a few reefs to give you an idea of what daily changes look like.

Guam:


FL Keys (during the summer, which is when there is the least variation):


Puerto Rico:

Telling people they should not care about temp swings is not helping anything. There is no denying that temp swings causes some stress

Not worrying about temperature swings helps the corals keep their natural tolerance to thermal stress. I have yet to see any evidence in the primary literature that normal temperature swings are a source of stress. Brian Helmuth's work that I mentioned earlier shows exactly the opposite. There was no stress response to increased temp up to 90 degrees from a coral kept under fluctuating conditions.

The idea that keeping a lower temp makes corals vulnerable to higher temps, while valid, is not an adequate reason. After all, the converse could be said about maintaining higher temps; that they make the corals vulnerable to lower temps.

That's not quite what people are saying, but it's not true anyway. People are saying that if you keep things stable then corals are more vulnerable to any change in temp, higher or lower. Even if things aren't stable, keeping corals on the low end does make them more vulnerable to increased temps. However, it's slightly easier for corals from higher temps to deal with colder ones.

[Rewd]

Great thread. The temp thing has always baffled me too and I agree completely with Peter and greenbean. People need to stop stressing about their tanks and just enjoy them.

[aninjaatemyshoe]

Is there a link to access this work by Brian Helmuth? I'd like to read it.

"4.) If the fact that temperatures in the 80's are completely natural and that temperature swings occur multiple times a day on a natural reef isn't convincing to you then we're just going to have to agree to disagree. You should also consider the many very successful reef aquariums maintaining temps above 80 and having temp swings as not convincing."

I wasn't doubting that these temperatures are natural. If you carefully read what I wrote, I was doubting the direct correlation of what works in nature works in the aquarium. Certainly, natural conditions are something to strive for, but we have to accept some limitations. This is why I'd prefer to model my aquarium after what has been found to work within the aquarium hobby, not directly after reefs themselves (I don't have nearly enough resources to do that). Furthermore, I never debated that other people have had success with higher temperature tanks with temp swings. Its just that I view it more of a case of good luck and maintaining other parameters very well than a case of what one should follow.

"3.) Greenbean nor I are advocating someone strive for wild temperature fluctuations. Simply put, if your temperatures are going up a few degrees slowly through the course of a day when your metal halide lights go on it's nothing to worry about. Not only that, it's quite natural and very similar to what happens on a reef. "

Followed by a comment by Greenbean:

"No, just allowing the temp in our tanks to swing back and forth doesn't replicate nature. It's much slower than what happens in the wild. When I was working in the Bahamas one of the guys at the research station had temp loggers placed all over the reef, (which was recovering, not declining). There was a 5-8 degree variation everyday and at least once that I saw there was a 6 degree change within 15 minutes, which was the periodicity of his readings. When I was doing my work nearby I saw too many 3 and 4 degree changes to count and at least one almost instant 6 degree change, which you can REALLY feel when it happens."

I see some discrepency between what is suggested in terms of temp swings (few degrees warming over the day from MH vs. 6 degree shifts instantaneously).

This debate is starting to get wearisome. I'm not going to be able to convince you guys that we should strive for stable conditions, you guys aren't going to be able to convince me that wild temp swings are a good thing in the aquarium I'll read the Helmuth article if I can get access to it, then I'm out of it.

[capn_hylinur]

oops just got corrected on another misconception --thanks peter--
Feeding clams cyclopeeze is not recommended due to the size of it--one should stick to phyo.
Also lighting is not as great a concern with adult clams as the young since they can rely on established filter feeding more then the young

you have to love this thread

[Peter Eichler]

For the fourth time... Just because we are pointing out the conditions on a reef does not mean we're telling people to go out and try to replicate it. The original point was... "Stop worrying about your daily swing in temperature from your lights heating the water. There's no need to go buy expensive chillers or controllers to always maintain the same temperature. In addition to being pretty natural the temperature swing may be good for your aquarium inhabitants and make them less likely to succumb should you have a more major temperature swing. In closed aquaria I wouldn't suggest testing the limits of this, but if your swings are under 5 degrees from day to night I wouldn't worry much." At no point in this thread have either of us suggested big temperature sudden swings or testing the extremes of the temperature range for home aquaria.

Also, if you look at some of my other misconceptions you'll see that I suggest other parameters be maintained differently than what might be found in nature. I've never found temperature to be one of those things. In other words, don't make it sound like I'm suggesting we should follow the conditions of a reef when that's not how I go about my reef keeping practices.

[Pmolan]

My temps over the last week.
My reef = Happy reef.

[zemuron114]

i personally worry alot about temp swings.. why? because i had a considerably higher temp swing then i normally do this summer in Boston when my tank hit 88. It was consistantly at 79-83 for a long time. 5 degrees doesn't sound like much, but it killed, 5 flame wrasse, rhomboids, lineatus, helfrich, tiny goldflake.... and started to deteriorate my hammer corals and killed 5 frags of SPS.

This to me is something worth mentioning and being concerned about... ? Its cut and dry when i look at it, or atleast from my experience.

Isn't it a proven fact that if the temp fluctuates more the 4 degrees in a 12 hour period it can cause enough stress on fish to cause ich? I've heard that multiple times from different "experts".

Just a thought. Overall, this is a great thread

[cayars]

I can see this happening zemuron114. You've got what could be 9 degrees (88-79) of change going on there which is pushing it.

However, if your tank is running hotter in the summer during the day with lights on and cooler at night say maybe down to 79 then the thing to do is run/adjust the heater so the night time temps top out at 82. The corals get more used to the range of 82-85 during the course of the day and then have more "tolerance" of a couple of degrees either way from the tanks "natural" average.

In other words don't fight the temps but work you system into them. If you don't have a cooler don't sweat it but use the heaters to keep the tank more stable in the upper range!

That might sound strange. Use your HEATER instead of your COOLER in summer but it's true.

I've got 300 gallons outside (uncovered with no protection or UV filtration) and 1000 gallons inside all connected together. My night time temps would fall to about 75 with day temps at around 85. Instead of trying to cool the system down to 81 or 82 I instead heat the water at night to keep the temps at 81.5/82 and allow the tank to fluctuate in the 81.5/82-85 range daily. If it's a little hotter out and I go up to 87 or so it's no big deal this way. Same with a little colder if the heaters can't keep up at night.

I've got a bunch of fans and another 2K watts worth of heaters I can turn on if needed via the aquacontroller but I don't have my fans turn on until temps are over 87 and I don't fire up the 2nd array of heaters until temps go below 79. I WANT my corals to get a daily range of temps only a degree or two below the natural reef (since it's cheaper for me).

As for other parameters I keep Alk in the 10-11 dKH range and keep calcium at 420-440. I keep my pH pretty steady with about a .2 daily change but normally keep it nailed at my target of 8.45-8.50. I think pH should range in the 8.3-8.6 range like on the reefs. I keep ORP in the 380-420 range (trying to dial in 380-400). I'd allow Nitrates approach 10 but they never do in my system and test at 0 on my tanks these days since I've got so much sand and rock. I took my nitrate reactors off line last week so I'll see if nitrates come go up at all. I keep PO4 by meter in the .2 range which doesn't cause cyno or other problems but allows there to be enough in the tank for normal function. Mg, Strontium, Iodine, Iron, etc are tested about once a month and adjusted slowly if needed.

I don't do water changes and run a mixed reef tank, ray/shark tank, outside pond & trigger tank all of which are heavy stocked (expect pond cause it's new) and joined together. I do take water from my main system for QT use via UV filters and I skim wet with 3 protein skimmers (4th one ready to go online if needed) so I do add "some" salt water to the system daily which so far has taken care of micro nutrients.

I know many people will say you should do water changes but I don't have anything I need to export that I'm aware of and I test all major elements at least monthly and make corrections if needed. I add 10-30 gallons of salt water weekly to the system so I know my micro nutrients are taken care of. Hence no expensive water changes for me.

Carlo

PS If I did do water changes I would use 2 small pumps and change out a couple of gallons everyday so I never have to worry about stressing the system. I'm not a fan of water changes over 10% unless it's a dire emergency. I think normal water changes cause far more problems then temps do...

[zemuron114]

Keeping it hot is not what i would want to do though. Most of the Fairy wrasses in the industry are collected in cooler temps. Long term they can't be kept in higher temps. That is my theory as to why most people have a healthy fairy wrasse one day and it is gone the next...

good idea though... i never thought of it that way.

[Peter Eichler]

Originally posted by zemuron114
Keeping it hot is not what i would want to do though. Most of the Fairy wrasses in the industry are collected in cooler temps. Long term they can't be kept in higher temps. That is my theory as to why most people have a healthy fairy wrasse one day and it is gone the next...

good idea though... i never thought of it that way.

However, back when lower temps were quite common people had even more issues keeping fairy wrasses alive than they do now. I think they simply don't ship well and have a harder time with the acclimation process in general than other fish. There are other families of wrasses that are routinely collected in warmer water and they have even worse survival rates. Lastly, I don't know where you're getting that most of them in the industry are from cooler/deeper waters. A far as I know most of them are from shallower waters with only a few species coming rom deeper waters that would be cooler.

[cayars]

If it's worth anything I've got a handful of different wrasse and they are all thriving well is 80 temps. I've had 4 for over 2 years, 1 for about 6 months and a couple for a couple of months but they don't count since they haven't been in the tank long enough. If a fish lasts 6 months in a tank generally speaking it will make it long term. I think the large majority of fish that expire do so under 6 months so until that point I don't consider it successful.

Carlo

PS running tanks hotter on purpose in the summer seems to "contradict" the advertisement (chillers/coolers) we see/read and goes against "conventional wisdom" but once you stop and think about it, you find it makes a lot of sense and solves the problem.

[tonyf]

Originally posted by greenbean36191

11.) A UV sterilizer will kill everything good or bad in your tank and significantly reduce disease, food, or filtering capacity.

Even when UV sterilizers have near 100% kill rates of the organisms passing through, in recirculating systems they don't make a huge impact on the overall populations. They are limited by the fact that the breeding population in the system is always much larger than the number of individuals being killed. They can also only kill those organisms that are in the water column. There are numerous experiments confirming that the use of UV sterilizers on recirculating systems either has no significant impact on parasite populations or on infection rates. [/B]

Yes and no. A benefit of UV is taking out water-borne pathogens and algae spore. After 18 months of battling muddy brown water, a UV unit cleaned up my tank overnight. I have not been without UV since that time.

Tone

[Peter Eichler]

Originally posted by tonyf
Yes and no. A benefit of UV is taking out water-borne pathogens and algae spore. After 18 months of battling muddy brown water, a UV unit cleaned up my tank overnight. I have not been without UV since that time.

Tone

He's refering mostly to parasites. A scenario like yours in one of the few times I would actually suggest a UV sterlizer.

[Rue]

Great thread guys...picking up lots more info!