when is the cycle over

Rogergolf66

Ok I have been reading alot it seems I get some slightly differant oppions

I thought the cycle was over when my amonia and nitrite read 0 and I have nitrates?

I have read that the cycle is over when the amonia nitrites and nitrates read 0, but I would think if you don't have a DSB or other denitrafication system setup the nitrates may never read 0. So I would be waiting along time to add fish.

What do you think?

Roger

mHeinitz57

you are correct. The nitrogen cycle is over when ammonia and Nitrite read 0 (or close to it) and nitrate is beginning to show. That means that the bacteria needed to convert ammonia and nitrite are present and growing in the tank. Tanks with live rock can also play a role in denitrification as well but often nitrate will still show in low ammounts even in those setups.