3 y.o. mandarin in a 46g. aquarium.

Yes, taking out all sponges and floss type filter pads definitely helps. and didn't you say you run purigen and GFO? That will help with the nitrates and nuisance algae growth.

And cyano is a bacteria, and is caused by a bacterial imbalance in the tank. Usually it shows up on the sand bed and pumps, and where ever there is a lack of flow. You can try to balance out the bacteria in the water column with certain products out there.

Microbe lift 'special blend' is what I use.

 

dowtish, thanks a lot for the advice, and I think I'll do something like that once my mandarin will shed her mortal coils. But I really do not wish to change the way my aquarium looks now, because, well, my mandarin ain't dead yet.