What should I do about a QT tank?

[ArcticRain]

I didn't know where to put this but, I thought here would be best. Sorry if this has already been asked.

My Betta has fin rot so I am going to put him in QT with AQ salt with 100% water changes for 10 days. I can't put him in a real QT tank because I keep my house very cold and I could not use a heater in a tank that small. I thought of maybe putting him in the Petco cup i got him in and floating him in the water. But that seems cruel and it might sink. So my questions are.

What can I use as a QT tank that can still be heated but isn't to big?

Also, can I just keep the pitcher of treated water out that I don't use, so I don't have to keep making new water? Thank you!

[Pataflafla]

Tupperware floats. you could float it in his tank if it's big enough to keep him warm. It also provide a bit more room than the cup depending on how deep a tupperware you're using.

I think an empty butter tub could work too if you have any. that's even more room if you get the big tubs.

Overall the cup wouldn't be too bad for him if you keep it stable. you could put the lid on it and tape it to the side of his tank to keep it from floating everywhere and tipping.

[ArcticRain]

Would I have to buy new Tupperware or could I just use what I have?

[Pataflafla]

You can use what you have. Just give it a good rinse in hot water to make sure all the soap from washing it is off.

[ArcticRain]

Ok. Thank you! Another question. Do I need to thoroughly clean his tank since he has fin rot?

[Pataflafla]

I wouldn't. Just do a standard water change and it should be ok. It just needs to be kept a bit cleaner whle he has open wounds to keep infection away. Since you're going to qt and use aq salt with him, that'll take care of infections he might have now.

[ArcticRain]

Ok, Thank you! I found a little critter keeper that can float in his tank, I will put that in his tank today. Hopefully he will get better soon! Thanks again for all your help!