i wasnt commenting on how many bettas in a 15 gallon tank, i know 6-10 bettas can live good in there if they get a long, what i was complaining about was having 20 bettas in a 10 gallon tank, they fish must have been unhappy having such little room, probally scared to move far as to lose there terrotory.
we all have our own opinions about bettas, personally i think 20 bettas is too many in 10 gallons, plus its overstoced
what i seem to find rude, and especially from you jade, is you say its a waste of space having 5 bettas in a 15 gallons, i thought you liked to give your bettas the best care and plenty of room with other fish with the bettas it would look nice.but then again, you do keep your bettas in 1 gallon tanks, again, too small (dont bother going on about the water quality if good etc and its better then those cups, blah blah, its still to small IMO)