Diatoms / Shallow sand bed maintenance

[lastlight]

I have a diatom outbreak I think. Layer of this brown/orange algae and tons of bubbles bleeding from my sandbed. I may have made things worse by stirring this algae up to release the bubbles I'm not sure. Been doing this for a few days and now I'm not sure that's a good idea. I've heard stirring a shallow sand bed is good. Some people say don't disturb but I think that pertains to DSBs? After I stir up the sand the layer returns and the bubbles are produced again within hours if the lights are on.

What's up with this and what's the best way to manage/deal with it? I've heard these are part of new setups...never had this with my first tank.

And where would the diatoms come from? Won't a membrane remove diatoms from our tap water? I've stopped stirring my sand for now. Also I notice the bubble production seems to be photosynthetic...well it really gets going when the lights have been on a while. But they come from INSIDE my sand.

Any ideas? And is this issue also linked to phosphates/nitrates and not just diatoms?