I have not had a diatom problem since a week after removing all bio filters in my tank and I only have a 30gal with 7 fish. Lots of waste being produced in my tank, but the nutrients are removed between my LR and my skimmer. My nitrate test kit by seachem starts at 10ppm and doesn't register anything. Follow the link and look at my pics for proof.
I just looked at your pics, nice tank!! Hope you can fix the problem. I noticed a window close to your tank in the first pic on page 3, is it letting sunlight in your tank? I'll shutup now, you obviously know as much as I do.
[ August 22, 2001: Message edited by: rblehm ]