how to determine if tank is 'matured"

[justjoin]

Hi

Pls advise - as above subject.(A planted tank)

thks

[bclee]

Generally, we are talking about cycling the tank. That means building up the bacteria for breaking down NH3 and NO2. You will know when the cycling is completed by testing for NH3 and NO2.

When the fish is added, the fish will excrete NH3. If you test the NH3 & NO2 daily, you will find the NH3 level will start to climb and peak after a few days. The bacteria for breaking down NH3 will start to build up. This bacteria will convert NH3 to NO2. NH3 level will then drop while NO2 will climb and peak. Now the bacteria for converting NO2 to NO3 will build up. In some cases, the cycle may repeat. When the NH3 and NO2 level has constantly stay zero or close to zero, you tank have cycled.

However, in heavily planted tank, the observation may not be exactly the same. This is because plants consumes NH3 and NO3.

Generally, if you test NO2 and found the level constantly stay at zero, you are safe.

BC

[vinz]

Read this article by Chukk Gadd, an active contributor to APD. It talks about setting up a new tank and cycling (or rather, not cycling). Make your own conclusions though.

If you go to his article list, there's another article furthur down the list which also talks about cycling.

[bclee]

If I am not wrong, plants do not use NO2. Maybe some botany expert can comment.

I feel that the main concern is NO2. As long as there is no NO2 accumulated, it should be safe.

BC