Water changes: good or bad?

[Dr. Mac]

Just my experience: I do not change any water, use to 25 years ago, but not now. I have very active 3-4 inch live sand beds, lots of live rock, large skimmers, calcium reactors, daily small doses of B-Ionic, top-off with RO/DI, 400 watt MH 20,000K plus blue PCs or Actinic VHOs, sump/refugium with numerous species of macro algae and live rock, lots of large fish and feed several times daily. Average readings: pH=8.2-8.3, alk. 3.5-4.0 meq./l, CA 450-500ppm, Nitrate 0-2 ppm Nitrate-Nitogen (frag 500 gal. grow-out is O NO3-N, 180 gal tanks with parent colonies and many fish avg. 2 ppm NO3-N), total of over 1000 gallons of reef tanks, literally hundreds of different SPS, LPS, and soft corals, extensive propagation (about 1000 frags now), excellent coral coloration and growth and very healthy fish (Example--in one of my 180 gal. tanks, avg. 2 ppm NO3-N, fed 3-4 times daily, 8 inch Imperator, pair flame angels, large Yel. tang, 6 inch Powder Blue tang, 8 inch Hepatus tang, spawning pair of Melanopus clowns, 3 Bubble-tip anemones, at least 50 different corals--never any water changes, corals fragged weekly, fish healthy-clowns spawn every couple of weeks). Fossa and Nilsen in "The Modern Coral Reef Aquarium" vol. 1 also state that they do not do more than 10% water changes a year and feel it is too disruptive. As in so many other aspects of this hobby, there are many ways to get to the same end, can't say one method is really better than another, I base opinions on results long-term. Just another view on the subject.

[simonh]

I have an interesting observation from my fish only tank. I only do 25% water changes 4-5 times a year. The system is 35 gallon with live rock with some sand for asthetics. Currently setup for over 2 years and no problems at all. Lighting is 2 florescent tubes (about 40W total).

Nitrate runs about 20ppm
Phosphate is at 2ppm

They are rather high but seen as it is fish only and no algae grows i don't bother.

Just recently when I had a flatworm crash in my main tank (discussed in another post somewhere on the board) I was forced to move many of my corals and clams into this fish only tank while i sorted out and removed the flatworm toxin and rest of the flatworms from my main reef tank.

I upgraded the lighting on the tank with a spare 150W MH so the corals would get enough light. I expected the tank to be rampant with algae and cynao within a week with such high levels of phosphate and nitrate. 3 weeks later and I still don't have any cynao or hair algae. This made me think that maybe other nutrient such as iron are lacking and this stopping algae from starting to grow? (I am now trying to reduce the phosphate levels while my corals are in the tank but only have them to 1ppm at the mo)

I agree that water changes are good (I perform monthly 25% changes on my reef tank) and they can correct many problems in a tank (often when people experience poor coraline or coral growth). And may even help by reducing trace elements added from foods!!

Just an observation that by not doing water changes the tank ends up not been able to grow hair algae nevermind corals?

-Simon

[This message has been edited by simonh (edited 09-22-2000).]

[Larry M]

While responding to another thread about tank problems, and giving the often-stated advice about doing a water change first, I realized that not every one thinks water changes are a positive thing. IME, they have solved a lot of problems and to me they will rejuvenate a tank that has become "stale" over time (poor coral growth, color, and appearance).

I have gotten to the point that I almost think you can't do too many water changes. I think when done correctly a 50% change or even more does no harm and a lot of good to a tank.

But yet I see many who are very reluctant to do a large change, or to do them very often.

What's your slant on that? :)

------------------
Larry M

"My Dad could build--or fix--anything. Just give him a hammer, a saw, a piece of wire, and a stick. Then get the hell out of the way."
In response to the question, "Where did you learn how to do that?"

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[razorbackfan]

Larry I followed your advise, did a 50% water change and everything perked up over night. I also notice that when I do a 10% water change on my 110 every 2 weeks, after the water change my coral and fish seem better. Maybe it's the addition of new trace elements?

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Jim - GO HOGS GO!

Visit My Reef Tank (http://themoneypit2000.homestead.com)

[BrianD]

Hi Larry,

I like doing w/c in my 180 periodically. It seems to give everything a boost. I usually change 20% or so when I do one.

An interesting thing, though, is that when I set up my 125 about 4-5 months ago, I added some uncured rock to the tank and let it run with just powerheads and a skimmer for over 3 months before adding any livestock. I just replenished water from evaporation. I have since added a Naso tang, a mandarin, and a leopard wrasse, all fish that are touchy about water quality. I did my first water change a few weeks ago due to the deaths of a couple of cukes. Sometimes I wonder if by doing water changes we remove the planktonic growth we are striving to keep in the tank.

Just rambling :)

Brian

[Steve Richardson]

Well.. when you have a puny little tank like my 75G, its easy to ramble on and on about water changes. Weekly ones at that.

However, if I had a 180 or larger tank.. I think I would be *far* less excited about the prospect. We're talking about a lot of work here.

Also keep in mind that a 50% water change (especially if you dont have a huge sump) may mean that you are having to move around some of the animals in the tank.. since they might be exposed as the water level drops. That isnt always possible either if you have large chunks of rocks overgrown by polyps & mushrooms, or whatever...

Soooooooo....

I agree with you 100%. A big water change is like blowing fresh air into an old locker room. I'm a big believer in it.

But I can also see how it can be a tremendous P.I.T.A. on a big system, and can understand why people try to explore other ways of 'restoring' a tank that is starting to look a little whimpy after running for a couple of years.

-S

[ReefDawg]

I guess it would all depend on the system, just like everything else does with the hobby, But I think the main thing is being consistant about how ya do it, keep it regular.

[Dwayne]

Yes, water changes are important, at least in my mind.

As ReefDawg stated, consistant and stable parameters seem to be as important.

Just more ramblings.

Dwayne

[KASESQ]

Larry-The only way I am winning the hair algae wars is with 50% w.c.s and on a 230 gal system that is a lot of work. I use an old Eheim submersible to pump out the old water on to my lawn (doesn't seem to hurt the lawn)and then with a series of dedicated trash cans with Rio 2300s (I know, I know, but these pumps run so hot I don't need an extra heater to bring the new SW up to temp.)I add the (week old, seeded with cup of tank water/barrel)NSW to the tank. IME brief exposure to the air doesn't seem to hurt any of my inverts (no SPS, but all other kinds).fwiw, Kurt.

[KASESQ]

P.S. even with 50% being changed it takes EIGHT w.c.s to reduce nitrates and phosphates to 0 per the charts. Oy vey!

[Doug1]

Clean waters gotta be good if its same temp ,yada,yada,yada.
Its east to setup a drain line (valve controlled) to get water out of the tank, while pumping it in with a small powerhead. If it takes an hour to change a trashcans worth that shouldnt shock anything and in/out flowrates matched up means no low tide syndrome :)

------------------
Reef as though your life depended on it, yours might but the sea's does.........Doug ReefTank administrator
visit www.thereeftank.com (http://www.thereeftank.com) userfriendly and flame free

[Lars E]

I have found that my tanks look better with no water changes.

When I first started, I did water changes on my 29 gal about once a month. Then I stopped doing them for various reasons. After about 4 months with no water changes the tank changed dramatically. I started getting calupera growth, things popped out of the liverock that I had never seen before, mushrooms started going hogwild, my anemone not only lived in captivity but started flourishing (died after doing a waterchange . . . that's a diffrent story).

Anyway, IME with _my_ tank setup and _my_ inhabatints, so far leaving the tank alone has worked best.

Lars.

[alde]

I find that very small water changes work for me. I change about 2 gallons every 2 weeks in my 65. I was doing 10% every 2 weeks but with the smaller water changes things look better and have more growth.

Al

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He who feared he would not succeed sat still.

[bjmumy]

I use water changes to replace trace elements. I don't dose ANYTHING. My calcium reactor takes care of calcium and alkalinity and water changes do the rest. I try to do a 5 gallon water change every week to every other week on my 75 gallon reef. I think for my system, that is plenty to replace the trace elements. In addition, who knows what might be building up in the tank that the skimmer is unable to remove. It makes sense to me to do water changes to remove anything that might be building up over time (organics, metals, who knows what else).

Brian

[Frisco]

I'm with you 100% Larry... but I think this points right to the difficulties we have discussing things in a text based forum like this based on our different perceptions... I mean, when you and I (and others of course) discuss the purity of our feed water, the degree to which we equilibrate it upon mixing, the degree to which we match the salinity and temperature, etc, we are all looking at theses things with different life experiences which affect our perceptions and expectations. Making a major water change without going through some serious prep work can really be a potential disaster in the making. But despite these difficulties, ensuring that we do whatever is reasonably possible to maintain near reef-flat water quality is paramount to a healthy tank. In my mind, that means doing periodic major and frequent minor changes, even when it means going against the grain and challenging conventional wisdom... JMO

[bmw]

I'll give a short-timers slant. :)
6 months ago I put in the lr/sl. I did 20% water changes every 10 days. 2 months ago I went to 25% every 2 weeks.
My diatom bloom lasted about 3 days. My hair algae epsiode went maybe a week and was never really bad. I am not sure I would recoginize cynobacteria.
Everything, everything, has grown-polyps, mushrooms, lps, gorgos, sponges, soft corals, brains, xenia, corraline, caulpera, fish, shrimp, crabs(uh-oh)- stuff all over the rock.
I would be afraid to change my routine at this point--know what I mean? :)
b.

[bmw]

I'll give a short-timers slant. :)
6 months ago I put in the lr/sl. I did 20% water changes every 10 days. 2 months ago I went to 25% every 2 weeks.
My diatom bloom lasted about 3 days. My hair algae epsiode went maybe a week and was never really bad. I am not sure I would recoginize cynobacteria.
Everything, everything, has grown-polyps, mushrooms, lps, gorgos, sponges, soft corals, brains, xenia, corraline, caulpera, fish, shrimp, crabs(uh-oh)- stuff all over the rock.
I would be afraid to change my routine at this point--know what I mean? :)
b.

[Staceon]

Dr. Mac,

I am attempting to go to a no water change tank on my 3 year old reef, been about 3 months so far and everything is going well. I have a few questions for you:

*since you frag so much, are you also sending those frags out or trading with fellow hobbiest? If so you place small amount of water in the bags, isn't this the same as small water changes?

*do you have the yellowing of the water from the organics?

*do you ever have to add salt? My thinking is you lose some over time?

*your system sounds incredible! Can we some pics?

[Anemone]

Staceon,

Outstanding point (and strangely enough, exactly what I was thinking ;) ). A few years ago, I had an aquaintance who ran a small-time coral/fish sales business. He claimed to do no water changes. But after talking to him, it became apparent he was changing 1-2% of his water every week by replacing the water he shipped out to his customers.

Kevin

[Larry M]

Interesting responses. Another one of those areas where there really is no "right" or "wrong" way to do it. If what you are doing now works for you, I say keep doing it.

However, if a water change looks like it causes a disruption, or in general makes things look "bad" in your tank, maybe there is something wrong with either the salt or the technique used. I don't claim to be an expert in this area, but here is what works for me:

1) I use RO/DI water.
2) I use Instant Ocean salt.
3) I try to get a lot of air and turbulence into the mixing process. I use a Mag 7 and a venturi powerhead in a garbage can. One of these days I will buy the propeller that Bingman describes. :)
4) I don't dump the salt in all at once, sort of let it slide in gradually. Once all the salt is into the container, I move the powerhead around to make sure it all gets dissolved as soon as possible.
5) I use a heater to bring the temp of the mix up to the tank temp.
6)I match salinity with the refractometer.
7)I use Amquel or Prime to neutralize any ammonia produced by the new mix (there will be some)
8) I mix it until the ph is up around 8.2, more or less.


Once all this is done, I change water. It might be a few hours, or sometimes I just let it go to the next day. I have never had a problem using salt mix that has aerated for just a few hours if the above criteria are met.

I don't worry much about most corals being exposed for a short period of time.

I can honestly say I have never lost an animal due to a water change, nor have I even seen evidence of much stress with the major changes.

FWIW

------------------
Larry M

"My Dad could build--or fix--anything. Just give him a hammer, a saw, a piece of wire, and a stick. Then get the hell out of the way."
In response to the question, "Where did you learn how to do that?"

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[Vins Fins]

Here is my opinion on water changes.I don't believe in changing water in LARGE amounts, but i do believe in high water quality. The only time i would ever do lrg change is if everything in my system was looking terrible. In my 180 i skim wet, approx
1.5 gal per day. I tested the salinity of my skim and it was around 1.022, my system is around 1.025. so in fact i'm doing a water change every day.approx 50 gal per month. i add about 6 cups of salt to the tank every week.using this method keeps the parameters the same, so there is no need to take out LARGE amounts at any time.
Think about it when you do large changes you are also taking out good water. when you use your skimmer your taking out a much higher % of bad water.and by adding salt every couple of days the trace elements are replenished.I keep a large # of fish for a reef tank and i don't get algae blooms and my corals are getting huge.

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Vinny

http://home.twcny.rr.com/vguarno/

[Dwayne]

Larry - that's alot of work. Not saying it's wrong (probabably better than my way), just different from the way I do it.

Here's how I do it:

1: Fill two 5 gal buckets with water from RO tank.
2: Dump in two scoops of IO salt.
3: Mix for a couple seconds with a paint mixing attachment on the end of a drill.
4: Dump new water in sump and syphon out old water from tank.

Takes 15 minutes. :)

Dwayne

[This message has been edited by Dwayne (edited 09-22-2000).]

[JSM]

This may be a dumb question , but everyone in my area uses Coralife Salt and everyone here uses Instant Ocean. Why do you guys not use Coralife? Is Instant Ocean that much better? I've heard coralife dissolves better. I've been using Tropic Marin but it's just getting too expensive and I'd like to switch to something that I feel is good quality but I don't have experience with anything else. Can anyone give me pros and cons on this? Maybe I should have started a new thread?

Janna

[Larry M]

Vins--You might be taking out "good" water, but you should be putting in better. Do you really add 6 cups of salt a week to your 180?? Your skimmer must be set very wet. That's a lot of salt, enough to make 12 gallons of saltwater at 1.025. How many gallons of skimmate do you remove a week?

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Larry M

"My Dad could build--or fix--anything. Just give him a hammer, a saw, a piece of wire, and a stick. Then get the hell out of the way."
In response to the question, "Where did you learn how to do that?"

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[Dr. Mac]

Your point about removing some water from my frag system is true, yes--a small amount of water is "changed" when I sell or trade frags, I would estimate maybe 0-20 gallons monthly from the 500 gallon system. I do not seem to need to "add" salt to my other parent colony tanks and in those I seldom am selling or trading corals so no real amount is "changed". I would love to post some photos of my systems if someone could walk me thru the process for this BB, sorry, I'm not a "computer person", please be gentle. I can e-mail photos of my systems for anybody interested if you email me at drmac@dmv.com. As far as water yellowing, I use carbon and a Poly Filter pad in an HOT Magnum filter for 2-3 days a month rotated between all my tanks and the water seems to not yellow when I use this filter on this schedule, I do use the large size Aqua C skimmers on my 180 gallon tanks and an ETS 1400 on my 500 gallon frag grow-out system. Because I use the 20,000K MH lamps with VHO actinics or PC blue lamps, they are very blue and can tend to mask yellow water, but I don't see a major difference after using the carbon for a few days a month. If I put some water from any of my tanks in a white bucket, like a used salt bucket, I do not see any yellow discoloration, it looks almost the same as freshly mixed salt water. These tanks have been running for a number of years and were seeded with sand I had in tanks that had been running over 15 years. I have also regularly added worms and other critters for the live sand beds. I have the following tanks, 500 gallon frag grow-out consisting of several plastic vats connected together with a 110 gallon sump/refugium, 2 180 gallon parent colony SPS and LPS tanks with lots of fish, a 265 gallon system (180 plus 65 tied together with 20 gallon sump/refugium) for soft corals, 46 gallon office tank, 10 gallon home office tank with way too many fish and corals, and a 2 gallon reef tank. The only ones that get any water change at all are the 500 gallon SPS and the 265 gallon soft systems when corals are sold or traded, at this time that is irregular at best.

[Staceon]

Dr. Mac,

I too am trying to set up a web page. If you can get the pics to the computer(thats my problem) than it will be pretty easy. There are all kinds of free places that will host a site for you. For example here is one place that host only sites about SW:
http://members.saltaquarium.com/

Most of the sites are set up with programs that are like "set up wizards". Meaning they walk you thru it.

Might sometime check out the "lounge" here at RC. Just post the question about the website, or if someone is willing to do the leg work for you and post the pics.

Glad to have you aboard. I look forward to hearing more from you, and seeing some pics of what sounds like some really nice tanks. Show them off. :)

[jim]

sounds like most replies concern Reef tanks.

What about FO tanks?

I do a 25% change every month on my 500 gallon set up. It takes @ 20 minutes with plumbing from the tank to an outside mixing / holding tank.

Jim

[clownkev]

JSM- Apperantly, Coralife salt is not used because it contains a neurotoxin in it (i believe lithium) that is not good for inverts especially but fish as well, in the long term.

[ejloomis]

I did not change water on my first reef tank, which I kept for about 14 months. My reason for this was my belief that changes are more stressful and disruptive to the tank than any benefits they may confer. After all, with most water changes the substrate is disturbed, the fish are frightened and stressed, there are rapid water parameter shifts, etc.

That tank did well without changes, but I've nonetheless begun 15% water changes on my new tank. Two things persuaded me to start:

i. It was pointed out to me that some trace elements might be available only in new saltwater that, over time, could reach dangerously low concentrations without changes, eventuating in a system crash. Of course I don't know if this is true, but it seems plausible.

ii. I found a way to change water slowly and stress-free: I just mix the change water in my top-off tank, and then slowly siphon it out of my aquarium. The top off pump automatically replaces the lost water.

Of course this method is slightly inefficient, in that a small portion of the freshly made water is siphoned out. But barring an infelicitous placement of the siphon relative to the top-off pump inlet, this won't amount to more than a 15% loss on a 15% change (and normally much less). It's easy, and I really recommend it.

[marinelife]

I have to add my two cents, In my 75 and 35 I have never done a water change even after adding live rock. My 75 is lookin great, 35 is still being stocked with rockand stuf but doing good. On my 180 I only do a water change if I see something not lookin right. The tank seems to do better when I do not do any water changes. I do one or twice a month add some supplements to the water to help out but other than that I do not mess with the tanks. I have found that the less I mess with them the better they are. Well that is my 2 cents!!!!!

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See my 180 Gallon Reef Tank at Http://www.glasscity.net/users/ehall or Http://go.to/marinelife

[Joe Kelley]

Hello all! I on the 400 gal system I do a W/C every 2monthes of 100 gal. I have an old 100 gal acrylic for the mixing tank. It is very light and I lift it with a hand truck into my room. RODI the water takes about 36 hrs and mix for a few hrs. I use IO, but recently got a good deal on redsea 150 gal. I notice only + effects. I like the locker room analogy. Pretty grose if you think about it!-". I change only the water from and to the 230 gal refugium, this is left off line for a few hrs. Then back on. This method has worked very well. My skimmer is set to pull out some water(HSA1000), I check the SG every week. I add a few cups of salt a month if that. PPT at 37.HTH
Joe

[Vins Fins]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Larry M:
Vins--You might be taking out "good" water, but you should be putting in better. Do you really add 6 cups of salt a week to your 180?? Your skimmer must be set very wet. That's a lot of salt, enough to make 12 gallons of saltwater at 1.025. How many gallons of skimmate do you remove a week?
<HR></BLOCKQUOTE>
Hi Larry,
I guess what my point is, I would rather take out the worst water which is what is coming out of my 2 ets reef devil 3 skimmers. I add 2 cups of salt appox every 2-3 days. I meassure the system salinity which will very from time to time between 1.024-1.025. From what i remember when i used to do the bucket thing,
it would take me 4 cups of salt to = 1.025 in a 6 gal bucket. using tropic marin

Also yes i do have the skimmers set to very wet, i found that with many fish in a system
it is the best way to keeep things looking great. approx 50 gal per month is probly how much i change. This system works very well and i find it easier then doing the buckett thing.Your tank parameters also stay much more constant.
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Vinny

http://home.twcny.rr.com/vguarno/

[This message has been edited by Vins Fins (edited 09-22-2000).]

[jimhobbs]

I got a sorta different slant on it than some of the above posts...I'll go into the procedures in a bit; but not now...I just now got home from a busy day...


Water changes are a breath of fresh air for the tank...I work in the HVAC industry and deal with sealed systems, that are super effficently filtered with all the special micron level filters...Even with all this filtering and treating, often it is desired to introduce some outside air!...What applies to air applies to water as they are both fluid in their chemical "dealings"...When I change the water. I'm "Opening a window"


Facts for jimhobbs:
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>
[*}I keep small systems[max 29gal}
<LI>I do a min of 35% [b]weekly[/i]
<LI>The skimmerless 10 gallon gets 50-60%
<LI>I have a change out system{routine} involving precision equiptment
[*}I make very few trips to the LFS due to deaths; and, give xenia and mini stars away weekly[tanks are swarming with them!]
<HR></BLOCKQUOTE>

The rest{details} I'll post in a bit, I'm fixin to throw a ribeye on the grill


Point is, if done right large percentage changes are SAFE and beneficial to my tanks...I've proved this over time...

Back in a bit...jim

[Bomber]

Does anyone use raw sea water besides me? I do a 25% water change at least once a week.

[BrianD]

An excellent link:
http://www.reefs.org/library/article/t_brightbill_wc.html

Brian

[Spudster]

About 6 months ago I started using raw sea water in my tanks. The tanks have never looked better! I change 10 gallons in my 160 and 2 gallons in my wifes 20 gallon invert tank every 2 weeks. I know 6 months isn't very long, But, i am having great success with this and plan on continuing with it. Besides every 2 weeks I have a great excuse to take the boat for a ride.

Landescaper...Islamorada....no fair!


Spud



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Well Doc. . . it all started when I got this old, empty, tank. . .

[O'Man]

I have gone back and fourth on this for years. I am back to no changes and only add fresh ro water to replace evaporated water. I do use some additives, though. All my tanks are small reef tanks. Have two 38 gallon tanks and one 20 gallon tank. All my tanks have deep sandbeds with plenums. Keep LPS, SPS, good variety of mushrooms and button polyps.

[Larry M]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Vins Fins:
[QUOTE]Also yes i do have the skimmers set to very wet, i found that with many fish in a system
it is the best way to keeep things looking great. approx 50 gal per month is probly how much i change. This system works very well and i find it easier then doing the buckett thing.Your tank parameters also stay much more constant.<HR></BLOCKQUOTE>

Vins--that is an interesting approach. Maybe some of the people that post with nuisance algae problems could benefit by doing this. Maybe I could benefit by doing this. :) I think I will try it for a while and see what happens. Thanks for the idea.




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Larry M

"My Dad could build--or fix--anything. Just give him a hammer, a saw, a piece of wire, and a stick. Then get the hell out of the way."
In response to the question, "Where did you learn how to do that?"

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[Vins Fins]

Thanks Larry,

when i start to see algae creeping up, i always crank the skimmer up a bit more and it seems to work every time. I think that these super skimmers that they make today make it easier for reef keepers to be able have some fish in our tanks and still keep the corals looking great. I believe that people who have these advanced skimmers actually need to have some fish in there tanks,if they don't they probly
end up taking to much out of there system and
possibly doing harm to there corals.

when you start out skimming wet, the skim should look a light tint of brown. If you don't have a lot of fish in your 125 i would try only skimming 1/2 gal per day to start.in my tank i have a good load of fish so to keep the algae down i am skimming 1 1/2 gal per day.I'm still experimenting with this amount because my 180 is still quite new, but i must say this is the first reef tank that i've had that has started growing the coraline on the back of the tank glass first, usually i get the stringy stuff first.

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Vinny

http://home.twcny.rr.com/vguarno/

[Ironreef]

I change 10% monthly. When I clean my tank and skimmer sometimes 6-8weeks. I belive in w/c but not to many but each systems diff as long as corals grow it doesn't matter but i belive the bigger the tank the less you need.2g evap daily I add ro water(kalk) and feed heavy and the food has alot of stuff thats needed.

[mengerin]

I don't do regular water changes.

Axel Tunze had some research that showed that the rapid osmotic pressure varients caused major problems with the microorganisms and bacteria and thus negatively affected the nitrate process.

If you read his book, he discusses the osmoregulator and the affect on nitrates.
His approach mirrors a lot of what was said in _the modern coral reef aquarium_.

Cheers,
Matthew

[Larry M]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by mengerin:
I don't do regular water changes.

Axel Tunze had some research that showed that the rapid osmotic pressure varients caused major problems with the microorganisms and bacteria and thus negatively affected the nitrate process.

<HR></BLOCKQUOTE>

mengerin--could you elaborate on how performing water changes when parameters matched the tank could affect this?



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Larry M

"My Dad could build--or fix--anything. Just give him a hammer, a saw, a piece of wire, and a stick. Then get the hell out of the way."
In response to the question, "Where did you learn how to do that?"

See my tanks at Northern Reef (http://www.reefcentral.com/northernreef/index.htm)

[jimhobbs]

Agreed! :) Matching the parameters of the tank is the key to providing as little shock to the inhibitants as possible...

I do it with a system of thermister monitored water temps, and a refractor to compare salinity between the two sources{tank-mixing bucket}...I circulate the water overnite in five gallon buckets, via mj1200 in the bottom...I have a controller hooked up to a heater that I clamp on the bucket...When it's time for the change, I recheck both the tank sg and the bucket sg....If both match, the full bucket is placed above the tank and the drain bucket is placed below...I start the syphon and simply move the hose from the drain buckt to the full bucket; thus reversing the flow...Total time for change once started-3min...None of the corals close up and there are no noticeable effects :)

[Bomber]

Hey Spud, are you using anything to buffer? Try 1 tbs. Arm & Hammer baking powder. You are definitely NOT changing enough water, tell your wife you need to be doing water changes every weekend ;). Jerel

[aLittletank]

Ok Keep my post in perspective I have a little tank (15 gallon long /10 gallons in a 15 gallon sump)

I change 20% weekly (5 gallons)
I skim lightly -piccolo air stone

Friday mornings - fill bucket with water, salt, power head, and heater. 5 mins

Friday night - add buffer check SG 1-2 mins

Sunday morning- siphon out 5 gallons from sump insert 5 fresh to sump 5-8 mins

At the most it takes 15 mins because i have a system set up and I know how much salt, and additives to add ( the first few times it took allot of tinkering to get it right)

bigger tanks would have a harder time with my schedule though.

I am but an egg, and if given over whelming data proving me wrong I could find other things to do with that 15 mins :)

Allen

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check out aLittletank!
http://www.alittletank.homestead.com

[This message has been edited by aLittletank (edited 09-23-2000).]

[mengerin]

Howdy Larry,

It's fairly easy to match temperature and getting a fairly close match on salinity. However, pH and hardness would be two parameters that would be very difficult to match. The ionic balance between new water and old tank water is going to be different. The macro and some micro items in the tank (especially those from the tidal zone) will not have much issue w/ the flux, however the bacteria walls are very sensitive to quick change in osmotic pressure and erupt.

Tunze's recommendation is to do a water change by dripping in the new water if one feels it necessary to do the water change.

Cheers,
Matthew

[ATJ]

I have six tanks are try to change 10-15% every two weeks. I believe in water changes for keeping nitrates and other impurities down and ensuring I maintain correct ionic balances.

(Matthew,
I am going to use some of your comments to support water changes. This is not meant as a personal attack on you.)
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The ionic balance between new water and old tank water is going to be different.<HR></BLOCKQUOTE>
This is the #1 reason to be doing water changes. One has to assume that the ionic balance of the new water is correct and that the old tank water is out. Going without water changes will result in the ionic balance getting further and further from "normal". There's no consumer device that's going to tell you how far out you've got it.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The macro and some micro items in the tank (especially those from the tidal zone) will not have much issue w/ the flux, however the bacteria walls are very sensitive to quick change in osmotic pressure and erupt.<HR></BLOCKQUOTE>
If this were true to any great degree, all of us that do water changes would have regular ammonia spikes. I know I don't. Further, anyone who has used hyposalinity treatment, and I have, will also know that gradually dropping the SG from 1.025 to 1.009 over a couple of days doesn't kill the biological filter.

Are fluctuations bad?

In the natural environment on the reef, things aren't as constant as people think, especially in the first few metres. Anyone who's dived would be familiar with thermoclines some of which the temperature can change by a number of degrees Celcius. Haloclines (change in salinity) also exists. Both are caused when one body of water moves in on another.

On the Great Barrier Reef, tidal variations are quite high. A variation of &gt;3m (between high and low tide) are not uncommon. This results in quite strong tidal currents and so water of different salinity and temperature.

Storms, which are all too frequent on the GBR, also bring with them fluctuations in salinity and temperature.

Most organisms can cope fine with these fluctuations - and some may even "expect" them.

Now, when we do anyhting less than a 20% water change, the mixing of the new water is quite gradual and is likely to cause less stress than any of the above natural events.

I find the Brightbill article on water changes overly simplistic and reads has his excuse not to do water changes. He claims that small water changes would take too long to get nitrate levels down from 20mg/L to 5mg/L. However, if regular water changes had been done in the first place, the nitrate level would not have got to 20mg/L. And if they had, due to a large nutrient import, regular water changes would be required to keep the levels at 20mg/L.

His comments on trace element replenishment are pretty good, however, I question how separate dosing of trace elements can be monitored.

And then, after dismissing small water changes with all sorts of calculations, he claims that even smaller water changes can somehow help with ionic imbalances. I believe that ionic imbalances should be treated the same way as excess nutrients.

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ATJ
http://atj777.tripod.com/

[CleveYank]

Water changes are good.
Like everything else.....too much of a good thing can be bad.....ie no tank stability.
So small but consistant is much better.

Find the balance.

[Ironreef]

I don't worry about ph,alk ect . My water is room temp. I will add it all to the sump @ 20% I make the salinity to whatever= if my tank is high I make it less or more if needed. My corals stay open everything is fine. i make sure the water is well aerated. I don't think its all that big of a deal. In my tank anyway. I belive w/c are important in the beginning if you have alga or nutrient probs but later it should still be done but maybe not as often. monthly but each tank is diff

[Bomber]

I agree with ATJ 100% the dynamics are exactly the same for our Caribbean reefs.

[This message has been edited by landescaper (edited 09-24-2000).]

[bmw]

I am confused.
I (from this thread) do more water changes than most=excecpt alittletank.
I am do--for my schedule(see above post).
Do I cut back? Do I keep on? Does it change from first 6 months to later?
Help!!
Thanks,
b.

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A Mathematician, a Biologist and a Physicist are sitting in a street
cafe watching people going in and coming out of the house on the
other side of the street. First they see two people going into the
house. Time passes. After a while they notice three persons coming
out of the house.


The Physicist says: "The measurement wasn't accurate." The Biologist
concludes: "They have reproduced." The Mathematician says: "Now if
another person enters the house, it'll be empty again."

[ATJ]

bmw,
Stick with what works. If your organisms are healthy and thriving then stay with what you have. I guess you could cut back and see what happens...

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ATJ
http://atj777.tripod.com/

[G-money]

I change 25-40% every 6 weeks. I simply can't see how removing old stale water and adding fresh saltwater to your system can do any harm to the macrofauna (assuming quality control), especially with fish in the system. I wonder how many folks convince themselves their system doesn't "need" them out of pure laziness! (or lack of time...HUGE tanks...) Sure, you may have a healthy system, but what would it look like with regular changes? Not any worse I bet, IME far better. I bet your critters would advocate them if they could! (am I stretching it?) Think about the stress a fish undergoes when first being introduced to a system. I would speculate that this is several degrees more stressful (esp. physiologically) than a (clean) water change (again assuming quality control). IME, most folks don't even acclimate their corals when first introduced, so how could a water change be worse than that?!!! The ONLY potentially negative factor in my mind is the degree of harm done to the populations of organisms you can't see (but still want). I think it's worth it. Just my two pennies...

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If at first you don't succeed, you're doing it wrong!!!

[lakerfan]

what do you guys think is better for a 90Gal tank?
a small gallon a day change or a 25% every two weeeks?