I have a new 75G tank with two 3" goldfish that has been up for about 10 days. Up until yesterday it had just an Emperor 400, now it also has an AC500. My plan is to remove the Emperor, but I am wondering if it might be best to leave both filters on there for a time. I've been testing every other day, and the water has been constant at 0 nitrite, 10ppm nitrate (same as tap), and 0 ammonia, until this morning when there was a slight hint of ammonia (.125ppm maybe - I need to get a better test kit).
At this point is there any bacteria of significance in the old filter, or is it still pretty much "clean"? I really want to take the Emperor off ASAP
(for reasons that belong in another thread
), but I don't want to disrupt any biological processes that may have started
Any advice is welcome.