[SubRosa]

You may or may not need a heater.First determine the fish you want to keep and adjust temp accordingly.As far as stocking levels go the old "one inch of fish per gal of water" is a crock.One four inch fish makes alot more waste than four one inch fish.Worry about the weight of a fish not its length.If you are willing to do large weekly water changes you can stock that tank much more densely than common wisdom would recommend,but you must build up slowly.As an example I once raised in a 29 gal tank over the course of a year a Black Ghost Knife from 3" to 14",a Fire Eel from 6" to 16",in the midst of a breeding pair of Rainbow Cichlids that were 3"-4" each,and 10 assorted Cory cats around 2" each.All fish were added as small fry and grew till I traded them in.But I changed 33% weekly without fail.Water changes are easy and cheap in FW.The solution to pollution is dilution!