Fish in. Did several water changes. Had to break the filters down, completely clean, replace cartridges. Would come right back within a week or so. It would clog the filter outflow, clog up the cartridges. The water did remain clear. No surface scum or debris. But, the filter was a mess! That’s why I switched to the TopFin Pro. These are not newly set up tanks. They’ve been up for some time! Beats me??
After setting up the TooFin Pro in both tanks, the water is crystal clear. I don’t know if this stuff will come back!
Maybe the pre-filter will catch it before it hits the filter. It’s only affecting the filter. The rest of the tank is fine.