Water Circulation & Dead zones

[NanoDrummer09]

Hello all, so i have a 40gal breeder thats been set up for almost a year now and everything is running well and cycling is all through. I had a red slime algae bloom a month or so ago and treated it and everything has been fine since. Im noticing though certain parts of my tank accumulating a brown algae on the sand bed. Not on the rocks or anything else, just the sand. I believe it is due to the lack of water flow to those areas so debris and crud is settling then creating the algae. Ive tried moving around my pumps but it seems to just move around these algae hot spots. Im currently running an eco-plus 594gph return pump and two Korilia 600gph one at each side in the display. Something I'm doing wrong? Not enough flow or placement? I haven't had this problem before in my past reef experience and looking for some sound advice. Ive never considered aiming my pumps at a downward angel but would consider that but then would be concerned about the surface flow of the water haha. Help a reefer out. Thanks!

 

[don_chuwish]

I'd say the overflow and return pump sending water back in at the surface is enough for surface agitation. If you want to try aiming the Koralias down more it's not going to hurt anything. Alternating flow pattern would help stir things up too - have one pump off part of the day, then the other pump off part of the day. Even 1 hour each would stir things up a bit more than just steady state.