HI, I have a 210 gallon aquarium that i bought reef ready. For my filtration I use multiple things such as two protein skimmers, a 55 gallon sump with live rock and bio balls in it for top of the line biological filtration, two 1,300 gph. pumps that have a small sponge filter attached to them, a vortex XL diatom filter, a marineland c-360 and c-530. With the canister filters what causes the nitrate spikes is the biological filter media such as bio balls and bio rings. I remove these and put the bio balls in the sump to create a circular motion in them so they collect as much bacteria as possible. I use the canisters strictly for mechanical and chemical filtration only. This resulted in fully balanced parameters. Some people think it is dumb to use a canister filter but it works for me and it works great for me. I have several great corals that look fantastic so I have no reason to believe that canisters are an issue. I do also use a phosphate reactor just in case of a spike. Filtration is such a complicated and difficult decision but we all make it through. I highly recommend canisters for mechanical and chemical use but not biological. I also recommend to diatom for crystal clear water and to remove floating bacteria and help with depleting ich.