[the_blue_tuna]

I have tried to find the answer to this , but cant. Does anyone know how long it takes to complete the cycle in your tank? What I mean is , in an established , healthy tank how long from the time a fish "discharges" to the time your macro assimilates the byproduct? Anyone have a clue?

[Reefland]

Hey Jim!

I don't think there is an answer to your question as there is no calculation (that I am aware of) and if there were it would have to include many unmeasurable variables.

How many waste producing animals are there and how much waste does each animal process and how much waste is there to process? I think these would be just a few of the variables.

Scott Z.

[Poseidon]

wow GREAT question... Never thought of the actual time required to "process" the waste. I agree with Scott in that it would be very difficult to calculate, but certainly not impossible. I think though even if it was calculated in a controlled environment it would not do much for the average aquarist. Example: lets say there are 5000 Nitrobacter and 5000 nitrosoma cultures in a 1 liter sample. them 1mL of fish waste is added. The water is then tested immediately for NH3 and then every 5 min after that for NH3 and NO2. Just guessing here, but after 20 min No readable NH3 and only 1ppm NO2 after 30 min no NH3 and no NO2 are present. What does that mean to us? We have no clue how many cultures of Nitrobacter or Nitrosoma are in our tanks, nor do we know how much waste is produced by a given fish in a day... We only need to know we can achieve a balance between the two and that when we add a new source of waste it takes some time to bring the tank back to an equilibrium state.

Hope this helps a little, Mike

[reefrunner69]

In an established aquarium that tests 0 for ammonia and nitrite, it can be assumed that there is sufficient bacteria to handle the job instantly. There obviously has to be some time involved, but I thin you are talking seconds for the current in the tank to carry the waste to the bacteria rather than miinutes.

[Ninong]

Originally Posted by the_blue_tuna

What I mean is , in an established , healthy tank how long from the time a fish "discharges" to the time your macro assimilates the byproduct?

Not very long. The fish "discharge" is mostly ammonia, which would be converted by nitrite bacteria into nitrite and then by nitrate bacteria into nitrate and then by denitrifying bacteria into nitrogen gas. If you happen to have macroalgae in your tank, it can take up ammonia directly as well as utilize nitrate. The process begins instantly. How long it takes I guess depends on the amount of the "discharge" to be processed and whether there are detritivores in the tank to assist in the process. An easier question to answer is how long it takes for food to be processed from the time it enters the fish's mouth until the time it becomes part of the "discharge." In some cases it is only a matter of minutes.

[Poseidon]

I knew Ninong would post on this one... Seems right up your alley!!!!

Good answer.