Get Selcon if you can. Many others don't have as much, if any, HUFA's. As far as feeding goes, blender mush will generally sink as will most frozen food IME. Most of the time it's eaten before it reaches the bottom though. Clowns are going to be most interested in floating food pieces. Getting rid of food on the sand is where your clean up crew comes in. I feed what my fish consume within a few seconds. I add a little food, it's eaten in a few seconds, then I add a little more. I do that 2-3 times each feeding and I feed twice a day. HTH