thought about temp fluctuation...

[AL ur Pal]

I was just thinking about how the temperature of your tank should not fluctuate too much... In the ocean, I remember how when you go deeper the water temp gets colder. I'm not sure how much of a difference it is, at least a couple of degrees. But anyways, don't fish swim all over going deeper then shallow again, and this doesn't seem to have an adverse affect on the fish, so does temperature with acclimation and temperature fluctuations over the day (in our tanks) have as much of an ill-effect as we thought? Just throwing a thought out there!

[MiddletonMark]

But most of our corals + inverts don't swim or travel that widely.

Lagoonal species may get variance w/ the tides, rains, etc ... but coral-wise, stable temp is more important.

[scottywags]

Have'nt you ever been in the ocean and all of a sudden the water either gets warmer ( not cause your girlfriend is next to ya! LOL) or colder?
I think that water temp usually swings 4-5 degrees just with the tides.

[AL ur Pal]

so why are a lot of people overly concerned with a 2 degree temp change over the day?

[69vette]

Because when something happens to their tank, they have to blame it on something, whether it's the real cause or not.

[MiddletonMark]

I haven't seen data one way or the other, but I know most coral researchers suggest keeping temperature variation to a minimum. I'm sure they know something.

I'm positive that most reefs don't have daily 2 or more degree fluctuations every day/night period. Sure, maybe every few months or something ... but that's not what's happening in aquaria. And that's what I personally try to minimize.

[marrowmuse]

Originally posted by AL ur Pal
so why are a lot of people overly concerned with a 2 degree temp change over the day?

Here's my non-expert opinion: Certainly there is some temperature fluctuation in any natural reef. In striving for stability of a reef tank in general, most people try to maintain a steady tank temperature, and they have the technology to do a pretty good job- almost too good of a job. The animals in these tanks become accustomed to a constant, regulated temperature, and if all goes well, they are never exposed to different conditions.

However, we all know that eventually something will go wrong, and when this does and the temperature strays from the constant, it catches the animals off guard. They are not used to temperature changes, and may be more adversely affected than they otherwise would be in nature.

I like to think of the analogy of growing plants in a greenhouse, where they are never exposed to the wind. Some plants will be more lanky, with a much thinner and weaker stalk than they would if they were outside where they would always be exposed to different wind conditions. If taken outside and planted, they could be blown over by a breeze that shouldn't ordinarily harm them.

Gotta keep in mind though that in our tiny closed systems, temperature changes can happen more quickly, and go to MUCH greater extremes than in the ocean, especially when something malfunctions- so it is very important to have good temperature control. Just some thoughts...

[dvb]

I think that it is much easier to isolate a problem in a tank if you can start eliminating variables such as tank temperature.

[Ewan]

In my opinion, it's the other variables that are dependant on temperature that would cause a problem in our tank. There is so much more than the actual temperature of the water.

In the ocean, we can assume that variables such as oxygen saturation are not a problem. In a reef tank, when the temperature changes 1-2 degrees, the entire ecosystem is changing. Oxygen saturation is very dependant on temperature, as well as salinity. When these items change, this invites room for other things to change....

Less oxygen could me more CO2... The formation of carbonic acid may occur.

The formation of carbonic acid would lower the pH in the system.

Lower pH could affect the toxicity of available ammonia (pH sensitive)


And these are only a few items.



With the MASSIVE amount of water in the ocean, stability is a given. Obviously, we can see how temperature changes affect dense communities of corals in negative ways in the natural reef. Despite the large volume of water.


just my opinion,

E.

[Ewan]

I might add that my SPS system reacts VERY poorly to temperature fluctuations. I have observed RTN events in the past due to higher-than-normal temperatures. Unfortunately, this has happened enough times for me to notice the trend in my own system. IME, there's nothing more devastation in a closed SPS system than a temperature spike.

My soft coral tank is much more forgiving in terms of temperature fluctuation. Makes me wonder why I'm interested in SPS at all. :D


Good topic.

E.

[AL ur Pal]

Ewan: Just to point out, I believe that the lower the pH, the less toxic ammonia is and the higher the pH the more toxic it is. Someone tell me if I'm wrong.

[nigle]

Oi!

So how can I agree with EVERYONE at the same time?

Since our 'tanks' aren't the ocean, what happens in the ocean can't be completely reproduced in out tanks, but we can illiminate as many of the possible varients as we can to illiminate as many of the 'shocks' as we can. Temp is one thing we can 'control' better than most.

Is 2 degrees a bad thing? I think we are getting nit-picky! Is 10 degrees daily a bad thing, I think so! no matter what happens in lagoons or near ocean currents.

I've tried all combinations of fans heaters lights mounted away from the water etc, and I have temperature differences I can't control [no AC] and sometimes the temp creaps up and can't be fixed until I get home.

As long as the changes are gradual the shock is less than a heater going nutz and cooking dinner. But if we can keep the differences to a minimum it's a good thing [martha].

Cheers!
nigle
!~!

[Agu]

My little ten gallon tanks fluctuate 3+ degrees a day with no ill effects. If you have small tanks it comes with the territory. If other parameters are maintained and there's good circulation and aeration I don't see where temp changes are a problem. However, if you're pushing the edges of maintaining a healthy tank, temp changes can push you over the edge.

jmo,

Agu

[Navyblue]

I agree that we have been overly careful.

In an open reef, especially shallow reef, temperature in the noon can reach over 85 F, and at night below 75 F.

As for salinity, imagine a tropical storm, or massive flood run-off from the river.

But I think the reason for such carefulness is our fish in captivity somehow do not have the resistance as in the wild. For exampl ich, ich is common in captivity but extremely uncommon (or virtually impossible) when you dive and see a fish with ich.

[PaintGuru]

Originally posted by Agu
My little ten gallon tanks fluctuate 3+ degrees a day with no ill effects. If you have small tanks it comes with the territory. If other parameters are maintained and there's good circulation and aeration I don't see where temp changes are a problem. However, if you're pushing the edges of maintaining a healthy tank, temp changes can push you over the edge.

jmo,

Agu


Totally agree here. Mine moves 3+ degress per day. The other thing to remember is these are not instantaneous changes, they are usually pretty gradual.

[kevin gu3]

My tank fluctuates 3 degrees a day too, but I'd rather it didn't. I've been in water where there was a cold thermocline, but I'm not sure thats the environment I want in my tank.

In the South Pacific the thermocline is way down. The warm layer is massive and it's temperature is not going to be affected by something as insignificant as a sunny day.

On a forereef the current is running pretty much constantly bringing open ocean water to the reef. In the lagoon OTOH the water changeover isn't so great, its fairly shallow and things can heat up on a sunny day. The extreme case is a tidal pool situation with big temperature and salinity swings.

So my thinking is I've got critters from all three regimes in my tank. The tidal pool and lagoon critters aren't gonna care much if the temp doesn't swing, but the forereef guys (acros) probably will. So I don't want any swinging going on. Just my 2 cents.

[Ewan]

Originally posted by AL ur Pal
Ewan: Just to point out, I believe that the lower the pH, the less toxic ammonia is and the higher the pH the more toxic it is. Someone tell me if I'm wrong.

oops! I do believe you are correct.