Does anyone have experience or currently run a ULNS (ultra low nutrient system, is that right)? I'm thinking of a ULNS without any fish, very minimal cleanup crew (maybe just algae eating snails, like trochus), bare bottom, huge flow. Through some research, it looks like some regular feeding and dosing would be needed if you don't have fish: 1. Amino acids 2. phytoplankton 3. daphnia, cyclopeez From reading all of this, it looks like you would actually not maintain a ULNS, but counter the fact that there's no fish as the middleman (or middlefish?) for feeding the coral. You would have to feed the tank anyway, either through the guts of fish or directly with small particle foods. The only upside is that you can control your overall nutrient levels in the tank, and be able to avoid too much bioload in the tank. The reason I'm looking this up is that I'm thinking of doing a fishless system, so that I won't have to be home every day to feed these dudes and to have a really clean tank with thriving SPS. But it seems like I may have a lot more work culturing food and would have to feed the tank everyday anyway. Fishless tanks are so boring too. Anyway, would love to hear if anyone has done it and what your experiences were!