Okiimiru wrote:
> "The other reason the tank's liquid testing is in neutral parameters
> is because I make a point of having over 100 trumpet snails (only to be
> kept somewhat depopulated by the loaches), olive nerite snails and ramshorn
> snails. The snails naturally clean the tank of all leftover food
> debris."
>
> Snails don't clean aquariums, not when you look at the big picture. They
> eat fish food (which would have if uneaten rotted to become ammonia) and
> convert it into poop, which degrades into ammonia. They just add a one or
> two day delay to the decay of the food. When their bodies decay when they
> die in your tank all that nitrogen they used to grow their tissues returns
> to the tank. No net nitrogen is removed from the aquarium. With plants,
> you actually do cut the plant tissue out of the tank when you trim the
> plant. Thus some nitrogen is removed from the system. Plants clean your
> tank. Snails don't.
>
> The total net nitrogen into your tank comes from the protein in the fish
> food you add. The total net nitrogen out of the tank comes from either
> water changes or plant trimmings. Snails do not change the net nitrogen
> balance on the tank.
>
> Accumulation = In - Out + Generation - Consumption
> Nitrogen in your tank = Fish food in + Plants taken out


I completely disagree with you with respect for I know you've been around for some time in this hobby. Nevertheless Okiimiru, snails, especially the malaysian ones I have, well over 100, possibly up to 500, for at night, the snails come out (when the room is completely dark, I sometimes shine a small flashlight into the tank, and there are literally hundreds of small to large snails roaming the walls of the tank, the rocks, the plants etc, cleaning every nook and cranny - they even leave behind their "cleaned" trails as proof)...snails are scavengers - outside of shrimp - the best around.

Snails eat algae and decomposing flesh can be of great benefit to the aquarium keeper. Snails are very thorough cleaners of glass and rocks and can get into the nooks and crannies.

Now I do agree aquarium snails, of all kinds, excrete ammonia into the water column. But the ammonia is so minute, that the levels of ammonia never peak above 0 (as all my liquid tests show).

Please let me try again to explain the concept of a mass balance. There was a typo with a + sign being where a minus sign should be in my previous post but I seem to have lost the ability to edit it. *shrugs* I'll try again here.

Let us assume that your aquarium is a closed system. The nitrogen in the tank water stays in the water and the nitrogen in the air stays in the air. The only way that nitrogen enters the tank is when you add fish food, as protein in the fish food. The only way nitrogen leaves the tank is either through
1. Removing water during a water change
2. Removing plant trimmings
3. Removing fish and snail bodies

Now, assuming that there is minimal exchange of nitrogen between air and water (which is a valid assumption), these three ways above are the only way nitrogen is getting in or out of your aquarium. If we're not doing water changes or removing fish or snails, the only way left to remove nitrogen is #2, removing plant trimmings. This is the method that I do in my tanks. I frequently trim the plants and remove plant tissue. Because I am not removing fish, snails, or performing water changes, logically the plant tissue that I am removing is equal to the fish food that I am adding to the tank because there is no accumulation of nitrogen in the water column.

The nitrogen mass balance is:
Accumulation = In - Out + Generation - Consumption
Water concentration + Substrate poop buildup = Fish food added - Water changes - Plant tissue removed - Snail/Fish bodies removed + Fish/Snail bodies decaying - Fish/Snail bodies growing - Plant growth

So with a net balance on nitrogen, you see that unless you are removing snails from the tank there is no change to the nitrogen in the tank because of the snails. If they live out their whole life there and live and die in the tank, there's no net change. That's why I said that snails do not clean your tank. Yes I understand that they do lick algae off of the glass and make the tank more aesthetically pleasing. In that manner they do clean the tank. In a way we are both right.

As to the feeding of fish, not every fish eats every other day. Vegetarians graze constantly. Top chain carnivores eat infrequently when they catch prey. Scavengers and omnivores eat nearly as often as vegetarians. How they eat in the wild depends on the type of fish you have. I understand that your not-feeding-the-fish-for-a-week technique was necessary to reduce the ammonia concentration and save their lives. They probably didn't enjoy it, though. There are alternative techniques you can use to lower ammonia concentration if that ever happens again, such as water changes and growing plants.

Alasse - that one week of fasting was back last year, and the fish may have "felt" better with a full stomach, so to speak but the fish were feeding off the tank organisms - it was only for a week out of six months...odds are in my favor

As for being lazy...actually I kinda miss water changing - I used to water change twice a week, 8 gallons on Thursday and 8 gallons on Sunday, I did that for over three years. It is not at all about laziness, it is about not disturbing the tank as much as I can plus the tank's chemicals are balanced, so there is no need to water change...............but Alasse gave up on my thread, so I'll just, well - whatever (((smiles))) - though for Alasse to give up on an argument is not like her...is it really you Alasse......just kidding

As for Okiimiru - I do trim plants sometimes, mainly if the plants are yellowing, but this isn't very often...I thoroughly understand the nitrogen cycle - thanks for breaking it down for me - so let me ask you a question: beings my liquid test results are ammonia 0, nitrite 0, nitrate 30 for a little over three months...are you saying, those test results cannot be relied upon? And though no fish have died (except for four platys due to stress from the redtail shark), the plants are flourishing and the water is clear, are you further stating that beings there is nitrogen in the tank, the tank is really on a destructive path and all the liquid test results and/or visual observations cannot be relied upon?

Please clarify your position

I would like to share with you what got me started with no water changing. I met a marine biologist, and we started talking about fish in general - he prefers salt water but he was well aware of freshwater aquariums as well (the guy was from Germany, I never met him again after this one time...anyhow) - I explained to him that I water change twice a week, 16 gallons a week, and he said that water changing actually causes the fish to stress because the chemicals being put into the tank all of a sudden wrecks more havoc on their systems than if there are no water changes at all...he did say, that there will be some evaporation and that will give me reason to supplement the water - and he was right - I put about 2 gallons of water a week into the tank. He even said, because I asked him, wouldn't the chemicals like ammonia, nitrite go crazy...and he said, in time, there chemicals via the nitro bacteria will ease or stabilize, and you'll, meaning, I'll be fine.

The reason I bring this up is, I got the idea from him - no water changing. And to my utter surprise, I found that the only reason the ammonia or nitrite goes up is because I fed too much - reason for the fasting - and once I figured out how to feed without having the ammonia or nitrite go up in the slightest, then I realized that German guy was 100% correct.

So who's right - the tank I have with proven chemical results; a marine biologist who knows fish better than most of us including myself; and/or those that are astonished by what I am doing.

Nevertheless, I would be interested in if you would answer those questions regarding nitrogen.

Thanks much

Natalie - I understand, and when I used water change, and when anyone on this forum would say they didn't water change, I'd always defend the argument FOR water changing...I was a huge water change freak, sometimes I'd, at the beginning of the hobby, a few months in, I'd take out 50% of the water, by bucket - I never used, for a little over three years, a siphon hose, I always used a bucket (I'd siphon water into the 5 gallon bucket, carry it to the tub, dump, repeat it a few times, then fill the bucket up in the tub under the faucet, then lift the bucket to the rim of the tank and slowly pour it in - I did that for 41 months to be exact).........but after listening to the marine biologist, and attempting no water change, I found it does work

now I completely understand rivers/oceans/creeks/even lakes continuously changing or re-shifting its waters - that too used to be my argument - if you ever peer over all my earlier threads in 2008-2011, that was my argument: water changes mimic constantly changing water in creeks, rivers etc...so I don't fault that argument

But I will say this much in defense of my new position: first I top off the tank with 2 gallons of water every week (sometimes 3 gallons, but usually just 2 gallons) and beings there is a high amount of current in the tank (even a couple pictures I just took of the tank show this), the current shifts the water about in the tank, even the plant leaves move or sway slightly due to this current...so there is constant movement in the tank except for the far right side of the tank, the water is calm (I wanted it this way for some fish prefer not too much current (the stillness is where the rocks are) plus the added 2 gallons of water in the tank each week amounts to a shifting of waters in the tank - and though I will agree with you, water changing 25% of the tank water per week is much more beneficial or creates a greater shifting of waters, the 2 gallons I do add is about 5% "water change".

But you know something, after debating the subject matter with Okiimiru (and Alasse etc) I started thinking: even when I was performing all those water changes, the fish and snails were in the same position as they are in now; that is, liquid test kits are the same, their behaviors are the same, the water is clear, there is a constant flow of current, the sunlight provides the lighting (this way even before no water changing), no filtration (even before no water changing) and no breakouts of disease such as ich occurred before no water change and after no water change...so if I never told anyone I have not water changed in six months, fish keepers and/or people in general would assume I was actually water changing because that is the thing to do as a fish keeper.

Of course you know me, I can text forever, so I'll leave it at this - I understand the water change position - I too defended that position - but if there is a current, no illnesses in the tank, chemicals are within their normal parameters, the fish are behaving normally, and the fish love eating every other day either frozen bloodworms or human foods like peas, chicken, liver, etc...what is so bad with no water change?

Once again, I welcome all comments regardless if they are negative or positive...I sure do hope Alasse would participate, for even though she is a tough girl, I truly respect her positions (one can tell simply by the pictures she posts in this hobby).

Thanks much

So, uh, not sure how clear I was on this, so I'll say it flat out. I don't change my tank water but once in a blue moon. My tanks go months in between water changes. Ammonia is 0 ppm, nitrite is 0 ppm, and nitrate is constantly in the lowest ppm category on the test strip, 0-20 ppm. My plants absorb the nitrogen and any toxins the water has. My fish are healthy and breeding.
Current picture of my 55 gallon Elassoma gilberti tank: http://gallery.nanfa.org/v/members/Eric ... 3.jpg.html My fish are one inch long maximum length in that four foot long tank, so it's hard to see them without zooming in. There are like 50 of them in there though.

Establishing a water-change-free tank is not unethical and is not unhealthy for the fish. Diana Walstad thoroughly explains the concept in Ecology of the Planted Aquarium. There is a lot of data published in the book about the mechanisms behind how plants absorb nitrogen and metallo toxins.

On the flip side, water changes are not unethical either. As long as the water coming in is dechlorinated and the same temperature, pH, DH, and KH as the water in the tank, there's no reason not to do water changes. I do water changes about once a month or three months for two reasons: tannin buildup (I don't like yellow water) and as was mentioned before hormone buildup (but by the plants, not the fish. Some plants commit chemical warfare against other species. I used to have Myriophyllum aquaticum and I did some research and found out it secretes a phenolic compound that inhibits the growth of other plants. I switched to other, less aggressive plants and make sure to do water changes just to make sure all the plants play nice with one another.).

I'm currently designing a water-change-free saltwater tank. Link if you're interested: http://forum.aquatic-gardeners.org/view ... =29&t=1429