Urgent betta help

Hey everyone so I recently bought a really nice koi betta but I realise that he hasn’t really been eating I then discovered that my tank is too cold (22+/) the issue is that I have mountain minnows and cherry shrimp that have to be kept cold. I do blame my self for lack of research I have another tank that is 37L that I have 5 pumpkin shrimp in would it be better for me to raise that tank to 25 and move my betta or can it survive at 22c until I set up a separate tank for it ?


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What have you been feeding to the betta? Perhaps it just doesn't like the food. 22 degrees is definitely cold for him, but I'd expect him to be able to survive. A lot of people keep their bettas in little jars with no heaters. On a cold day, I'd expect that water to get below 22 degrees.
On the other hand, what is the downside to moving him over to the 37L? Is it just shrimp in that tank? He should get along fine with shrimp.