KurtG wrote:

I have a really bad case of diatoms (or algae) growing. I added the
lights and 30# of rock a few weeks ago.

I was expecting my nitrates to be off the map, but they aren't bad.
Maybe about 30 ppm which isn't good, but good for me.

I switched to using distilled water until I get my RO/DI filter setup.
So, I don't think that it's silicates, but I have no way of testing for
that.

Last water change was two weeks ago, so I'll go ahead and mix up some
water.

My phosphates are better. Not great, but I've been using phosphate
beads and the levels have been settling.

I also have lots of bubble formation. I assume this is O2 from
photosynthesis.

So, how do I curb the growth?

--Kurt

If there are lot of bubbles sticking to/embedded in a coating of brown,
it might be brown cyano bacteria as well.

Had the exact same issue - but for me, nitrates were 0, phosphates 0,
and had a decent skimmer so I don't think disolved organics was an issue.

I think what was driving it was deritus on my rock and sand. I added 1
conch and about 5 cerith snails to my 20 gal nano and the problem was
solved. No more diatoms or cyano.