meri.akvarist.ee

Please excuse me, Estonian people, I hope most of you can understand English though, but I'm so exited about Tatu's presence in this forum that I can't suppress my temptation to utilize his huge knowledge in marine aquaristics (in photography and computers as well, but about these topics later ) to advise dumb newbies like me.

Tatu wrote on his homepage
I can imagine that regular water changes could help to remove waste products and restore the water ionic balance. At least most of aquarists hope so. But after making few calculations and using your mind, you'll find out that getting real results requires huge volumes of water to be replaced in your aquarium. For example see http://www.animalnetwork.com/fish2/aqfm/1999/jan/bio/default.asp Therefore I wonder, does water changes give a real effect or are we cheating ourselves? Besides, I've heard about aquarists, who, as they say, never do water changes and I know also a guy, who don't have even a skimmer and never used any additives, but relies only on water changes, and his tank is doing pretty well. You know, getting such contradictory signals its quite confusing for a beginner to choose the right (if such one even exists) way.

Question to all audience - what's your opinion?

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... and I think to myself, what a wonderful world!

Albert,

Thanks for your kind words but there's absolutely no reason to be exited

I agree that fixing a major imbalance in tankwater by doing small or even medium water changes is not practical (as shown by Dr. Bingman). Unfortunately sometimes it's the only way...

I think the first question you have to ask yourself is "Is freshly mixed artificial seawater better than my tankwater?" If you truly believe, that tankwater keeps getting better as the time goes by, there's no reason to do water changes

However, I think fresh ASW (artificial seawater) is much better than old tank water for a number of reasons:

* It helps to add some minor- and trace elements not commonly added by supplements. Boron, Vanadium and halogens are examples.
* It reduces DOM (dissolved organic matter) levels and removes compounds that are not easily removed by neither skimming nor activated carbon
* It helps to keep all dissolved elements at constant level relative to each other (see below) and allows you to use some cheap and/or fast corrective methods when needed without the fear of major ionic imbalances
* It allows you to easily fix salinity when needed

The article you linked shows pretty well how difficult it is to correct major problems by doing small ( < 30%) water changes. (You should note however, that many hobbyist actually do change large amount of water, for example, I do about 50 10% water changes per year).

But you are not going to have such problems to begin with if you do regular water changes with a good quality ASW! Here is a article by the same author which shows some "steady-state" calculations: http://www.animalnetwork.com/fish2/aqfm ... efault.asp

As you can see, even "small" (15%) water changes per month help greatly to keep the ionic balance in an acceptable range.

Lastly, I think that the most important reason to keep doing frequent water changes is the huge biomass / volume ratio in our tanks. Our tanks are many many times more "dirty" (or polluted) than even dying reefs in nature and inorganic nutrients concentrations can be tens or hundreds of times higher than in polluted reefs. In my opinion we should do everything we can to reduce the DOM- and inorganic nutrient levels in our tanks.

I really think that correct term for aquarium water would be DOM soup

There are also huge amount of anecdotal observations about positive effects of water changes - far too many to ignore. For example, in the lastest Advanced Aquarist's Online Magazine editorial (http://www.advancedaquarist.com/issues/ ... torial.htm) Terry Siegel tells about his experiences trying a "no water changes" experiment Quote: "In fact, I hadn?t changed water in my 700-gallon system for over a year, and the same was true for Greg. Recently, we both went back to changing water and compared notes. Both of us saw clear indications that the overall health of our sessile invertebrates improved. For example, after the water change polyp extension obviously increased."

All above with standard disclaimer: IMO, IME and YMMV

Thanks, Tatu! That's what I expected!

I agree 100% that water changes seems to be the only practical way to lower DOM concentration in the tank. I also understand that it would be impossible to give exact common advise how frequently and how big the changes should be, because it depends on many individual factors like quantity of fishes and other living organisms, feeding etc., ie, from the actual sources of DOM.

On the other hand, should I be careful about too frequent/too big water changes? It's obvious that every water change is also less or more stressing to aquarium inhabitants.
You know, there is a practical joke: nobody said that the life should be easy! OK, that was about human life. We MUST make our aquarium life as easy as possible, once we started with. That's why we are talking here, I think.

Rest of reasons you mentioned could be summarized as maintaining proper consistency of essential chemical elements and compounds needed for success. Do you think that a good quality ASW will beat numerious trace and supplement mixes available on the market? One positive argument could be that you know (if you know ) that your favored sea salt contains almost all elements found in NSW, what you usually can't say about those trace and other mixes (major trade secrets ). Do you think that in addition to regular water changes some sort of trace or other supplements are still needed?

thanks
BTW, did you know, a direct flight between Tampere and Tallinn will be established soon

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... and I think to myself, what a wonderful world!

albert,

Sorry for my late reply...

Yes, I would be careful not to make too big water changes. As you said, all sudden changes in water chemistry are stressful for the animals we try to keep and that's the reason why I prefer more frequent but smaller water changes.

I'm well known for the fact that I don't like to give any precise advice And the reason I don't do that is that (as you said) every aquarium is different and I really think that to become a successful reefer you have to learn the basic chemistry and biology of natural environment and then learn to apply them to your small ecosystem.

That said, in my opinion: don't change less than 15% per month and no more than 15% per week. In addition, don't change more than 20% at the time (unless it's an emergency).

BTW, I myself have noticed a big difference between the two salt mixes I've used when it comes to apparent stress after water change: when ever I changed water with IO (Instant Ocean) most of my corals slimed heavily. I can not see anything like that with the Tropic Marin salt mixes (Pro and "regular") ...

About the trace elements: though question If you read the article by Habib Sekha (http://www.advancedaquarist.com/issues/ ... eature.htm) you must wonder how much of the various trace elements in ASW are actually bioavailable... This is the reason why I have been dosing trace element product to my aquarium for a couple of months now.

As you said, it is impossible to know what elements and in what concentration a trace element product contains (not to mention their speciation). For this reason I've chosen a manufacturer that I know puts lots of research and thinking in their products and don't market their products as a "miracle" products

I think it is shown by the experience of thousands of hobbyists that for corals and other common macroscopic animals you don't need to supplement trace element for them to grow. On the other hand, their structural composition is very far from the nature... And I'm more concerned about the uncommon inhabitants anyway

Thanks again!

Oh, that sounds good to me! I used to make 12% changes after each second week.

At most I wonder about Habib itself Being an active scientist, the owner, production manager and who knows who else in his Salifert company, it's a miracle how he "holds the hands" of his customers in Reef Central forum.

Sorry, I'm little bit lost... You do add trace elements because most of them in ASW are not bioavailable and then you say that macroscopic animals don't need supplemental trace elements Are you adding trace for microscopic animals or did I miss something?

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... and I think to myself, what a wonderful world!

Exactly!

Ok, maybe I wasn't completely clear on that... What I meant was that you can't deny the fact that corals and other common sessile invertebrates do grow without additional trace elements. However, their CaCO3 structures differ greatly from their natural "brothers" when it comes to trace elements: they contain much less heavy metals than those living in nature. Our corals also reproduce sexually much less often than in nature (this could be for various reasons though). This is the main reason why I add trace elements. I never did before I read Habib's article....

The other reason is that for some reason our aquariums can support only a small fractions of the life in reefs. If you look at any closeup picture of the reef you'll notice that every centimeter of the rock is covered with life. Most importantly, sponges, tunicates, hydroids and bryozoans. Some people are somewhat succesful with sponges but no-one seems to have a long time success with any other above mentioned organisms. Why? Most people would say that it's because lack of proper nutrition but why then we can keep most sponges happy by feeding foods in 4-20 um size range. All above organisms eat basicly the same food in nature...

I have absolutely no idea if it's a lack of some trace (or minor) element or not but it doesn't hurt to try. For example, tunicates need iodine for feeding and they concentrate vanadium, iron and other trace elements in their blood. And who knows, maybe my corals are now able to construct their skeletons as they do in nature

As we all know, there is more than one way to create a great reef aquarium (or should I say a coral aquarium). We do know that if you want to keep corals, fish and other common aquarium animals alive you don't need to add trace elements. But if you try to advance your aquarium from a great to fantastic tank, you'll have to do something differently from the majority because 99% of the tanks are not fantastic And I'm referring to the biodiversity, not to coral health...

Hope this helps to clear my opinion

Hi, Tatu
Thanks, your answers cleared many questions


What a beautiful sentence Could I use it as slogan for this forum?

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... and I think to myself, what a wonderful world!

albert,


Heh, absolutely