I have a 65g tank with about 57g of water, a 1.5 - 2 inch sandbed. 2 clowns and 1 midas blenny. 3 blue leg hermits 1 emerald crab 1 conch 2 trochus 5 nassarius 5 cerith. I have 7 coral frags. I started the tank April of last year so just over a year ago. I run a canister filter and that isn't going to change. My problem is nitrates. I was doing 10g wc a week with saltwater from fish store. I have tested their water a few times and it's never even been 5ppm nitrate. My nitrates got up to at least 50 ( that's the highest my red sea test goes) so I started doing 20g weekly wc for about 3 months to get it down to about 5. I also added 1.5 bottles of matrix to canister filter (that's 3x what the bottle says for my tank) I also removed all mechanical filters except a 1/4 inch thick piece of filter ( I buy it at Walmart it's quilt batting) I change it out every other day. I have always cleaned canister out every week including propeller and I clean hoses about once a month. I don't over feed. I only feed every other day and nothing reaches the sandbed. I have tried blowing off rock a section every wc. Once the nitrates were a 5ppm I went back to 10g wc a week and of course the nitrates started going back up and within a month maybe less the nitrates back to 50ppm. I don't know what else to do. I can't keep doing 20g wc weekly. I don't want to get any more fish because that is just going to make it worse. Someone please help.

but during the test break, focus on target feeding better than you do now, continued water changes, and permitting no clouding from waste building up in your sand and rocks, ergo 1/3 of your current nitrate.

