[RussellTheShihTzu]

In order to see Velvet you turn the lights off and shine a flashlight on your Betta. This is Velvet:

I agree with ryry2012: He needs more food. Counting pellets is probably the worst way to determine how much to feed. Betta should be fed until their stomachs are gently rounded. Some pellets it takes three; some seven. It depends on the size of your Betta and the size of the pellets.

While stress is generally agreed to be the No. 1 cause of fin biting a definite reason for that stress has never been established; there are just a lot of theories from boredom, to hunger to fins to heavy...the list goes on.

However, based on what we see on this forum there are two overwhelming factors consistent in a majority of fin biters: Lights too bright (especially when the substrate is light-colored or white) and planting that is not dense enough. Betta are shade-loving, closed water fish. When a tank is too bright and too open they are stressed. The best way to describe a good Betta habitat, plant-wise, is you should never be able to glance at your tank and instantly spot your Betta. You should have to look for him.

 

[RussellTheShihTzu]

It's overfeeding in one meal that causes the problems.

BTW, did you look at him with a flashlight? Does he look like the Betta in the photo I embedded?

 

[RussellTheShihTzu]

Feed him until his belly is gently rounded a couple of times per day. I would make his main diet the pellets and frozen and use the flakes as a treat. You can feed him one meal of pellets and one of frozen. I feed a variety of frozen foods and only feed pellets when I'm lazy. But I have Betta-based community tanks so I go through a cube really fast.

You can thaw a bit of frozen in the fridge in a small medicine bottle. Frozen will stay good up to a week. When kept this way you don't have to let it get to room temperature as it will immediately warm on hitting the tank water.