Its been one week since i have bought my new used tank my nitrate are at 0 my phosphate are at 20 ppb with a hanna cheker i feed 5-6 pallet 2 times a day i have keep a small rock. for filtration i only have a filter socks should i add some biomedia in the middle chamber ? Am planning to change all the aquasquape The sand is caraib sea live sand the cyano is going off slowly i have 2 clown a cleaner shrimp one nasarius snail and 2 hermit crab i would like to add a watchman gobie and shrimp pair also a cardinal or a firefish one of my coral have bail out during the travel should i frag this head ? I have also notice a small red worm good or bad ? Here some picture of before and after