- Location
- Cape Coral, Florida
How high can I keep nitrates without doing a water change?
Dawn":3kl3y7b5 said:How high can I keep nitrates without doing a water change?
Bob,beaslbob":3o5ntigp said:Dawn":3o5ntigp said:How high can I keep nitrates without doing a water change?
I have seen nitrates measured with the aquarium Pharm**** test kit at over 160ppm.
Considering only water change effects, with doing water changes of 10% per week and 0 nitrates in the replacement water, the tank will converge to 10 times the weekly increase in nitrates. If the weekly production is 7ppm the result is 70ppm nitrates.
I have 0 phsophates and nitrates with no water changes in my 55g. What is important is eliminate the buildup between the changes. Buy doing that you remove no nitrates or phosphates with a water change.
Sure.Sponge_Bob":3qcbg3s5 said:...
Bob,
I have carefully read the above twice and failed to understand what you mean. Would you be kind enough to rephrase it and detail you explanation a bit more? The reduction of Nitrates is one of my main concerns in my tank at this time, so I'm very interested in fully understanding your point of view on the issue.
Of course there are various other metabolites and unwanted compounds that can build-up in a reef aquarium that will not be effectively dealt with via algae or bacteria. Just because we don't/can't test for them doesn't mean they are not a concern. That's where things like skimmers, activated carbon, water changes, etc. come into play.beaslbob":349qntdj said:But if the buildup between changes is reduced to 0 then water changes do nothing. In the case of ammonia and nitrItes the aerobic bacteria does it. With nitrates, phosphates, and carbon dioxide in my tanks I use plant life mainly macros in a refugium but the various algaes as well.
There are far too many variables with a complex and dynamic system like a reef aquarium for a statement like this to ever be valid.beaslbob":349qntdj said:Water changes will not prevent the accumulation of changes in trace elements as evidenced by the need to dose calcium alk and the like.
Oh... that's what you meant. Well, you forget an important factor in your basic equation : The evolution of the bacteria colony. In any given system, the bacteria count will always tend to match the given bioload present in the tank. Say you have 4 fish in the tank and you remove 2. Your population of bacteria will decrease acordlingly because of lack of food.beaslbob":3up30uap said:Sure.Sponge_Bob":3up30uap said:...
Bob,
I have carefully read the above twice and failed to understand what you mean. Would you be kind enough to rephrase it and detail you explanation a bit more? The reduction of Nitrates is one of my main concerns in my tank at this time, so I'm very interested in fully understanding your point of view on the issue.
Considering only the effects of water changes, the tank will converge to a point where the amount of a thing removed by a water changes equals the amount built up between the change. Therefore with a 7ppm increase between changes, a 10% water change, and 0ppm in the replacement water, the tank will be 70ppm before the change 63 after then rise up to 70 before the next change. a 20% change would result in 35ppm down to 28ppm back up to 35ppm. a 5% change 140ppm down to 133 up to 140. In each case the value before the water changes is (the buildup between)/(fraction of the change).
Which is the reason calcium and alk is dosed even though we do water changes. the changes will not maintain those or nitrates or phosphates or anything else.
But if the buildup between changes is reduced to 0 then water changes do nothing. In the case of ammonia and nitrItes the aerobic bacteria does it. With nitrates, phosphates, and carbon dioxide in my tanks I use plant life mainly macros in a refugium but the various algaes as well.
Some use DSBs for nitrate reduction.
The key IMHO is to get the tank itself doing the work.