"So…how is the drain/input to a CL pump achieved, filterless? If so then what is the long term effects of all the debris running through a pump? I have read that the CL system is self explanatory and is one continuous piece of plumbing with openings to allow the water to exit and enter, but I think that it could be separated and would be more efficient this way. The CL pump will pull in what it puts out and should not effect the drain or return of the sump/fuge return pump or calflo drain, right?"


Correct. Pull water from the tank, through the pump, and back in again. I think it would be your preference as to where you draw water from and return it, as long as there's no opening in the loop. Limited only by your imagination. No filters. I don't use one, but I wouldn't think detritus buildup inside would be an issue. At least not for a long time. Build it with ball valves and union valves so that you can take it apart to service the pump if needed.

Also, the nasty stuff doesn't rise to the top to be skimmed off. The object is to keep it all suspended in the water column. As the water is skimmed off, whatever is suspended in the water goes with it. I keep the surface water of my tank turbulent because it looks pretty under the halides (shimmer). 2 Koralias angled toward the top, just less than enough to cause a splash.