Just thought i'd share this before any one else makes this mistake. I made these reef racks out of PVC tubes and set up ledges around my tank with only the front exposed. the ledges created a about 10 inches caves depth with no water movements. The lack of water flow caused my nitrates to slowly creep up and cyna/red algae took over my tank. My elegance coral has since disappeared and i was getting roughly 3 cups of nasty skimmate a day. I have since taken them out and set up an all rock design to promote water flow. My skimmate is substantially lower and my my cyno and red algae are gone. If anybody want a reef rack for a frag or something just let me know.



