Photo Caption:This is an old Oceanic 30 gal. mirror-backed hex tank, which I re-sealed. Yes! I did, and it doesn't leak! I read Diana Walstad's book on dirt tanks and this is my first attempt. It's doing pretty well, I think. The tank is 24 in. deep, so lighting was a problem. Finally I settled on a clamp lamp made for warming chicks, and used a 5850K spiral CFL, 100 watt equivalent. I do 25% water changes weekly, and add potassium and phosphorus. 5 long finned danios, 1 Siamese algae eater, and 1 female betta. I discovered that the betta eats snail eggs, greatly reducing the population! Oh, and no added co2.