Algae is normal on rocks, just like sunrises are normal in the morning. I don't have green algae on my rocks. Diatoms are pretty normal too, most new tanks go through that stage. Those do just "go away" on their own.
I did at one time have a GDA/GSA problem in my 10 gallon tank, so I doubled my phosphate level. GDA is gone, GSA is very very minimal. Just throwing an idea out, do a little research for yourself if you want the algae gone.
The aqu
asoil does contain phosphates, Jeff and Mr. Barr are right. Adding more won't hurt anything, except your wallet.
