changes after using the heater

[coltin]

Grateful for this community, I really am. Got my betta about three months ago and everything's been awesome. Tank's finally cycled, he's been super healthy and happy, and I even got him a ghost shrimp buddy.

It's been getting pretty chilly lately, so I figured I'd get a heater. Tank temp was always around 75-78, but lately it's been dropping to 72-74 at night. Today I fired up the heater and it's now at 81. Took a few hours to get there, but now my betta's acting really weird.

He's just floating at the top of the tank with his fins all clamped up. Not his usual happy self, swimming around like crazy. Is this a bad sign? Maybe it's too hot in there? Help me out, please.

Normal aquarium heaters are generally made from glass with a rubber or plastic top, and they're designed to be safe for your tank. I'm not aware of any that give off toxic substances, so I think you can rule that out.

It's possible the heat from the other heater was too much for the shrimp, especially since he had just molted - sometimes they have problems during or just after molting and it can be fatal.

Just keep an eye on the water quality and make sure it's good, and the fish should be fine.

[bronze_shield]

I'm feeling a bit better now that I've got a new heater, it's lower wattage and seems to be keeping the tank at a comfortable 78 degrees. But I've noticed something weird - whenever the heater is on, my betta's personality changes, he goes from swimming around happily to just sitting at the top of the tank, looking like he's napping. I'm getting a bit worried, is it possible the heater is releasing some kind of toxin or something into the water? Also, I found my shrimp dead today, I think the heat from the old heater might have been too much for him, especially since he had just molted.