Hi! Need some advice on heating my 55 gallon aquarium. Just two questions. 1) What temperature? I will have orange-finned loach, skirt tetras, panda cories, neon dwarf rainbowfish, and rainbow cichlid. 2) What heater and wattage? I've read a ton of scare stories on the 300w Hydor Theo heater. I have the 25w heater and it works fine, but then again the scare stories are always about the 300w one. Which brand and specific heater and wattage would you suggest?