This afternoon I will be buying a used tank (30g) that comes complete with live rock and sand. The tank has been let go for that last little while so the rocks have some green hair algea on them. I was hopeing to use the rock in my new 90g....would I just scrap the algea off and then put them right in my 90g? The 90g is still cycling with no livestock! Now what about the sand? Can I use it or just toss it? I will be keeping the used tank and using it for a QT tank! I'm so excited that my 90g is slowly coming to life!!!