The sharpen filter might help define this guy a little more. Really nice pose, not an easy thing to get with these fish. I find they don't hold still very long. Lovely red colors, Veil-tail Bettas are so pretty.
you know fish are a very hard subjest to shoot. You need TONS of lights and flashes are a good way to get it. I use 2 when shooting pictures in my tank on top of the 500 watt lights I have. Try using more lights and point the flashes down on the fish. It really makes them pop out.