True 
Ken just stopped by to talk about some of the tank work we need to do. His back is giving him trouble, so we're going to shoot for a work day on Monday since I'm off.
He's going to cut the two lengths of ABS 2" pipe for the skimmer. The skimmer bulkheads are going to be centered on the inner half of the cutout.
We decided to place two bulkheads on each side at the bottom. Each centered on half the cutout. This places them 6" off the bottom and should prevent substrate from getting in them and still pull debris off the bottom quite well.
Ken just stopped by to talk about some of the tank work we need to do. His back is giving him trouble, so we're going to shoot for a work day on Monday since I'm off.
He's going to cut the two lengths of ABS 2" pipe for the skimmer. The skimmer bulkheads are going to be centered on the inner half of the cutout.
We decided to place two bulkheads on each side at the bottom. Each centered on half the cutout. This places them 6" off the bottom and should prevent substrate from getting in them and still pull debris off the bottom quite well.
. My point wasn't that it's not possible, just that a surprisingly small discrepancy with the level of the pipe will mess with the idea of even flow - that is why most manufactured skimmers use the comb style (that and to keep plant leaves and crap out). That and my experiences with trying to cut a pvc pipe like you've described have been less than favorable. IME (and IMO) it would be easier to cut a couple hundred 1/8" slots with a table saw and a jig, but that's just my .02