I don't know if it was the temp, but I have kept the temp around 75 or 76 and he is still ok. I did start using another thermometer that hangs over the side. You were right the strips are off a bit. I have read of others whose bettas react very badly to tank changes. If I were you I would make sure everything is VERY well rinsed - no soap! Make sure temps are the same and maybe try the transfer again after he calms down. Make sure you acclimate him slowly, maybe adding a bit of the new water to his cup before putting him in the new bowl. A .5g bowl is very small, that is one reason I moved Oscar to the 5g.