TL;DR: I have diatoms. I need help. I'm at my wits end. I can't even sleep because all I see when I close my eyes is brown algae. Well, not that bad. But it's awful. I have a 10 gallon divided betta tank. This is when I first set it up back in January but I did not add fish until February 14th. I've added some artificial plants and 2 male bettas. Unfortunately, I don't have a current photo because it's 2am and all the lights are off. I'll get one in the morning. I have a HOB filter which has Seachem Matrix, API Nitra Zorb and some sponge. I have high nitrates (40ppm) out of my tap, but between these 2 I usually see between 10-20ppm at each water change. I do a 30% or so WC every Thursday night and use Prime conditioner. I have a fluorescent bulb that's 16 watts (I think) and it's on for about 9 hours every day. Sometimes more, if I get up early that day. I have sand substrate from National Geographic that I bought at Petsmart. During my water changes I take a plastic fork and stir the substrate and try to suck out as much loose stuff as I can. The water even smells funny. Maybe more earthy rather than fishy, but still smells. I have another 10 gallon that does not have a fluorescent light (I have a glass hood and use my under cabinet LED lights) and there's one little tiny bit that I just noticed the other day on the sand but not nearly as bad as the other. I don't overfeed, I do my regular water changes with a good vacuum of the substrate and try and knock off as much of it I can and wipe down decorations and the glass. I'm so close to buying some Nerites and giving them the biggest buffet they've ever seen. Or rip this tank apart, dump the sand and put either bare bottom or gravel and pray that I don't go through a mini cycle. Help!