help with my betta fish issue

[florabug]

Yes, both tanks have a filter. When Pence had ich, we got a heater to keep the temperature up. I think it might have been too powerful for his small tank. The thermometer said it was 78 degrees, which is what I like to keep it at - either 78 or 80 degrees. We moved the heater to the 10 gallon now, and the temperature in there is also 78, but it feels really cool to me.

[florist]

It's been a while since I last posted, my previous thread was about Pence, my fin tank, who somehow miraculously recovered from Ich.

Although it's been a while, I'm now noticing something similar happening. Pence spends most of his time at the bottom of the tank and appears to have trouble swimming up to the surface to breathe.
He still comes up to eat at the surface but seems like he's having a hard time making it up there.

Any thoughts on what might be going on? Pence is over a year old now, his birthday was around January-February 2017.

Thanks for the help.

Bettas need consistent temperatures between 78-80 degrees. I guess it would've been better to get a heater from the start. For ich, temperature needs to be raised to 86 degrees to effectively get rid of it.

[florabug]

To clear things up, we actually did get a heater when we first got Pence, but we just upgraded to an adjustable one when he got ich. That's all.

[goldminer]

The feel test isn't reliable for checking water temp, I should've just trusted the thermometer.

[kindlux]

I like to keep an infrared thermometer handy for double-checking temps. It's super useful for verifying if something's off with my thermometer. I got mine on Amazon for under $20.