So I have a 680 gallon tank. I'm running an ATS with 2 screens that are 30x12". There are 4x22w CFL bulbs at 4000k with 2 more 55w flourescent bulbs. I run it about 7-8 hrs/day. My nitrites are zero and the nitrates are under 10. I clean my ATS weekly. The green algae that's growing looks a little slimy and dark. There are only 9 fish in the tank totally around 50".
The problem I'm having is I'm getting brown algae in the display tank. It's covering most of the bottom of the tank where the sand has blown off and is bare. Why am I growing algae when I have a scrubber and my water parameters are good? Am I not putting in enough light into the display tank?
I have been feeding more recently and the fish are getting a little bigger. But with 680g and another 150g in the sumps I would think it shouldn't be affected that much. I don't do too many water changes since I figured the ATS should minimize that. But lately I've been changing about 25% / week.
Any thoughts?