Hello Perry,
To tell you the truth, I've been considering changing my skimmer more then once... It's the only different thing from my previous build ( I had a Bubble Magus Curve 5 ) and I'm not really happy with it. It's a Deltec 1351 with adjustable DC pump and supposed to work in aquariums from 350 to 600 liters depending on stocking (mine is 170 liters total, not counting rocks).
There is some detritus building in the sump, but it's not that much and I clean it every week with water changes. Only feed my fishes once a day and they seem to eat everything and my RODI tds is 0 according to two different tests. Just the same I did in the past with good results, except the skimmer, so that may be the problem
Thanks