I set up a new tank to test the biohome. It is a 90 gal tank planted with anubias.
I have 50 cardinal tetras, 10 cory cats, 6 Filamentosa barbs and 6 cherry barbs.
I feed once a day. After the tank cycled, nitrates slowly creeped up to about 50ppms over the course of the next 2 months, by the 4th month, I noticed the nitrates are at zero.
I tested the tank last week and nitrates are at 10 ppm. I think it's because I did a 30% water change. Since the time I set up the tank(which is approx 6 months ago), I have only changed water 3 times.
I am running an xp2 with one compartment filled the a mix of standard and plus biohome.
I have never cleaned the filter, because I believe the exposure of the biohome to air will kill off the anaerobic bacteria.