Hello everyone! I am new to this forum and to the fishkeeping and especially saltwater. I just purchased a complete setup off of craigslist. I wanted to go bigger but I'll start with this. I purchased a 65G Acrylic with R24 refugium. The setup came with 100lbs of established live rock and 4 fish and 2 maybe 3 inches of sand. I finished setting up the tank last night and it looks cool. There were some things I am worried about but probably shouldn't be. For ex. in freshwater fish keeping, the water needs to be disturbed at the surface for the exchange of oxygen. Is this the same for saltwater? If so, how? There is also, i believe red algae or something in the middle of the sand visible in the front glass. My wife is yelling because she says it looks dirty. Should I move the sand around or leave it. Also, do sift through sand when I am changing water? It seems this tank is somewhat setup for reefs which I am interested in but I am also thinking of taking one of the live rocks out starting a fish only tank but I am unsure how to set one up with a regular tank. Do I need a tank setup with overflow? I know, I probably asking a bunch of stupid questions and I should do some research and I have. But there are so many different answers. Well glad to be part of a group who has personal experience.