Quick Question On Fishless Cycling

[Evad]

Why does the program ask you to get ammonia levels to 5ppm-6ppm? Why does it matter? If you start with 1ppm or 10ppm, isnt the result the same?

Did somebody calculate the amount of ammonia fish in a tank would produce and use that as a benchmark?

Just curious!

 

[OldMan47]

The result is not the same. The result of 10 ppm is dead bacteria. The result of 1 ppm is a colony of bacteria big enough to use 1 ppm of ammonia. The idea is that many people tend to add a heavy fish population on a per volume basis. To handle that much fish load, it takes a large bacteria population so you feed them enough to develop a large population without giving them enough to actually start hurting the bacteria due to excessive levels. The ammonia is the food for your bacterial colony and they will increase their numbers until there is no more food for them to use. When you get done with a fishless cycle in the 4 or 5 ppm range, you will have enough bacteria for a large but not excessively large fish population. What that means is that you could add fish to your setup rather quickly without seeing a large ammonia or nitrite excursion.

 

[waterdrop]

Plus, some of the science (such as it is.. the science is not very definitive) of why 5-6ppm is the optimal upper amount for the phase prior to the nitrite spike (what I like to call phase 1) is really quite interesting (if you like that sort of stuff)... When the level gets to around 8ppm it encourages a different species (different from the one we want) to outcompete and later, this imposter species can't sustain itself, dies off and must then be slowly replaced by the species that we ultimately want.

The reason not to go lower, down below 4 is exactly as oldman says, you want your ammonia oxidizing population to be big enough to handle the fish load you plan to stock in the tank.

~~waterdrop~~
ps. (hope I've got that science right, it was probably from the TFF science section somewhere..)

 

[Evad]

Makes sense. Thanks!