How sensitive are mushrooms/ ricordeas/ yumas to nitrates and phosphates. Looking to set up a 15g nano w/ HOB refugium,aqua clear filter. Don't have space for refugium. Will try not to overstock with fish. Try not to have a skimmer. Or do they need to have a skimmer? I have only kept FO tanks so just want to ask as how to prepare for setup. Do not want SPS, maybe after 6 months I would like a toadstool, frogspawn if tank seems stable