Diatoms ?

[Insahn]

Brown rusty spots are starting to appear on my tank glass. My tank is on its 4th week of cycle. Its still a new tank with just live rocks. If its diatoms do i have to wipe it off with a sponge or just let it stay till there's no more phosphates/silicates left

 

[Strictly Marine]

I would leave it alone for now. There is no point in helping them spread to the rest of you tank. Lawnmover blennies work real well in cleaning this stuff. Once everything is established, you should not have as much of the stuff as you do now.