Betta QT tank to cold!

[Leopardfire]

My betta has severe fin rot so I moved him to a 1 gallon QT tank of bottled water. It got down to 72 or 73 now which is way to cold for a betta especially when he's trying to heal. The smallest heater that I have is 8 watts and it's for a 2-5 gallon tank. I'm really worried that if I put it in, it will overheat him.

What can I do to keep him warm? Should I go to petsmart and try to buy a tiny heater or should I try out the 8 watt heater. When I used the 8 watt heater before I put him in, it brought the temperature from 74 to 78 in 10 minutes. I don't know how hot it will go.

[LebronTheBetta]

Just try the 8 watt heater. It won't hurt to experiment since there's a thermometer. Just check every 5 minutes and if it's over 82F, plug it out.
Can't you get a big enough container, fill it with water, heat it with the 8 watt heater, and put the 1 gallon QT in?

[Leopardfire]

Well, the QT is actually a 2.5 gallon critter keeper, but I just put 1 gallon in because bottled water is expensive. I could try floating it in my 10 gallon which I'm going to start cycling today. I'm not sure how to attach it to the cage though.

[LebronTheBetta]

You can probably duct tape it. That's just an idea, though.

[Leopardfire]

I put in the 8 watt, and so far it hasn't overheated the tank. It's about 76 after 1 hour. I'll keep watching it, but I think it will work out.

[LebronTheBetta]

That's better. And feed him live, frozen, or FD foods. He'll need the extra protein to rebuild his fins! And yes, FD foods do have a lot of nutrition!

[Leopardfire]

The water temp is still slowly rising. It is at 79 now which is good, but I'm worried it might overheat if I keep the heater in. Do you think I should take it out? I know it's bad for fish to go back and forth between warm and cold, so I don't want him to have a sudden temp drop and get stressed. Do you think I should try floating it in the 10 gallon instead?

[Wendyjo]

I would be concerned about the water being too warm. While warm temps are good for the fish in general, if the fin rot is caused by a bacterial infection the warm temps can actually make it worse (unless you are treating with a true antibiotic) as most bacteria thrive in warmer temps.

[Leopardfire]

I took off the heater. Hopefully the temp won't drop below 76 so he should be ok.

[Myates]

I use 25 watt heaters in 1.75 gallon tanks.. fluctuating the temps up and down like that can cause undo stress. An 8 watt won't go much higher than that.

You don't need bottled water, it's actually more detrimental than helpful to him.. even with fin rot.

2 tsp of AQ salt per gallon, daily 100% water changes (adding in salt + conditioner each time) for no longer then 10 days. Use tap water as it has the minerals the betta needs. The daily water changes will help keep the water extra clean like the bottled, but won't deny the fish the healthy benefits it needs through tap.

Normally it's fungus that thrives in warmer temps, it's never recommended to lower the temp when treating for fin rot- 79* is much preferable than 73*. No reason to lower it as long as the treatment is being done correctly.