I have a 56 column tank with a ac70 and eheim 2217 as mechanical and biological filters. I do 5 gallon water change with light gravel vaccuuming every two days or so. I have two cfl lights 23. watts (actual wattage it use and about 100 watt equivalent) . A compact sword plant (ferrtilize with seachem root tabs) doing real well, Just put brazillian pennywort into plain gravel substrate fert with root tabs. Floating i have salvanis and water sprites and planning lot of frogbits. Stock is 3 spotted rahaeal and 3 strips raphaeal, two feather finn catfish, and one calliichtys callichtys with only one firemouth cichlids. hoping to add some emerald corys to this mix would this be okay maybe 5 emeralds?