Hello, I bought a used red sea max 250 with live rock corals and sand. I got everything moved and set up last night. The tank looks like it hasn't been maintained for a while. The rock has some weird algae I'm not sure what it is but I thought I could take a took brush and scrub it lightly. Any idvice on how to clean up a beautiful neglected tank? I'll post some pics so you can help me identify what's happened.