Theo,
In my grow out tank, I use a sinking feed from Aquatic systems because it is so great on the fish...but a side benefit are the spectacular colors it seems to promote in fish. Check out the Tilapia and Pacu on my web site. The Tilapia are redish in color and the Pacu simply spectacular. The feed is called New Life Spectrum and it isn't cheap, but seems to be really good.
