i'd give you an id but everyone in the community has told you how to keep snakeheads and you've refused to take any of our advice. The tank conditions you have it in are disgusting and you don't deserve to keep fish
the reason why you have to do weekly water changes is because your tank is far too small and it seems like it has no filtration whatsoever. i don't care if you took the photo before cleaning, im telling as simply as I can, those conditions are not adequate...