I set up my 10 gallon 2 weeks ago. I did a 10% water change every 3 days until I noticed he was sick then I did 1 30% water change every day for 3 days, then 1 100% water change one day, then 2 10% water changes in 1 day. Then he died. I fed him Hikari Betta bio gold, as a treat I fed him Betta dial a treat. The bio gold I fed him 3 or 4 teeny tiny pellets twice a day. Every couple days I would skip the bio gold and feed him the tiniest bit if a treat, like the size of a pin head. I was only feeding him once a day, but, he was looking a little thin and internet research said just a tiny bit twice a day. He cleaned up all the food pretty quickly until he got sick.