Help on snakehead

Hi,
i recently bought a channa sp. fire and ice. Everything seems ok at first but after a few hours this are the problem im facing:

1. The snakehead has been jumping and banging his lips and head on the roof, which leads to scale coming off and blue black on the head and lips, is this normal? any way to help it less jumpy?

2. I read up that they need cooler water, but my tank temp has always been around 31 Degrees. will this be a problem? shd i get a fan or must i really buy a chiller?

Please help as im new on channa..