It is hard to tell from the photo, but it does not look that bad. How many fish in there? The Betta OK? He looks so beautiful. Try your best to make him happy. If he is the only one in there I would think he would do ok. I have one male betta in a 5.5g and he is doing great. Only have to take about a gallon out every week, plus I do have a small hob filter. I think bettas deserve some kindness. They are kept in such appalling conditions. I hope you find the time to take good care. They are extremely rewarding fish.