good morning... i have a few questions.. (i've been saving them all for one post.) last saturday.. i purchased a 30g hexagon tank with: an undergravel filtering system and two powerheads (i think they're called). we treated the water with stress coat, and the next day, we purchased some fishes.. 2 baby pink kissers and 3 blue gourami. now.. i really wish i would have done more research, of course, but it's a little too late for that.. all the fish seem to be doing pretty well, except one of my blue's.. he's staying very near the surface, and looks like he's having some trouble swimming. while in the fish shop yesterday, i spoke with a woman who believes my blue is having trouble with oxygen, so i bought an air stone for the tank and plopped that in there too.. i've also been having alot of trouble with the temp.. we have unplugged the heater, and are floating bags of ice to cool the water down to 74°-76°.. we've also been keeping an eye on the ph/nitrites/ammonias.. everything seems fine. any ideas? tips? suggestions? should i do a water change soon? when/how often do you think i should do them? we aren't adding any more fish for at least another 3 weeks.. good idea? think we should wait longer? we started this tank for my 7 year old son who's been very enthusiastic and helpful and concerned about his blue. i hadn't known before hand what i was getting into completely, but i am very committed to doing this right. thank you in advance for your help.. i've been all over the web this week, looking for information, and i must say, these are the best message boards i've come across.. you guys have a lovely thing going on here.. in anycase, enjoy your afternoon!