(i posted this in betta care too, but thought maybe i could get more of a range in responses if i posted twice!)
so i returned my preset heater yesterday that was only heating to about 70 in my 6 gal tank. i bought an adjustable one. the only problem was that it was huge for the 6 gal. so i switched the one in my 10 gal with the one i just bought and put the smaller one in my 6 gal.
i've been watching each heater like a hawk. making sure they don't rise too quickly or fall too quickly. well i did this for about half the day yesterday. and it stayed at a steady 76 and everyone seemed fine. well, yesterday the temp. outside was about 50*. so the heat wasn't on inside. unfortunately the temp. dropped to about 20* during the night (no heat on in the apartment). so when i woke up in the morning my 10 gal tank said 69* and so did my 6 gal.
well, all 3 of my males (in my 10 gal) seem to be doing the same thing. laying on the bottom of the tank. which is something they don't normally do. and my newest tiny male (who is in the 6 gal) is now swimming slanted and looks possibly a bit bloated (which i didn't notice until i did water changes and gravel vac about an hour ago). well everyone ate fine this morning and i turned the heaters up a tiny bit and they've both been at about 78* all day.
any idea why everyone is acting so funny? the only one not acting funny is my fin biting rescue who is as active as ever. could it just be the drops and rise in temps? it makes me sad to see everyone so weird.