Hi, we just set up a 20 gallon...

Question
Hi, we just set up a 20 gallon aquarium 3 weeks ago. The directions on the filter with a bio- wheel say that the filter should be replaced every 2-4 weeks. I just replaced it. Should I have waited until the nitrogen  cycle is done? also, the nitrite is 0.50 right now  I just changed 25% of the water two days ago. How often should I be changing the water when the nitrite is going up?

Answer
Hi Daniel;

It is best not to change the filter, but to gently rinse it in a container of tank water to keep it flowing freely. Every two weeks is good. If it gets pugged up too quickly it means you may be overfeeding (like most of us do from time to time). Feed less food anyway because with higher nitrites the fish aren't able to digest very well.

You can change 25% of the water every day if it is needed. This keeps some nitrite in there to let it continue to cycle, but avoids shocking the fish and gets the nitrites low enough for them to tolerate.  

Followups welcome

At Your Service;
Chris Robbins