I've had my SRO set up on my tank for a little over a year now. About a month or so ago it started overflowing about once a week. I've checked everything to try and fix it. There is nothing blocking the Venturi, the hose is clean and clear. I have it set in 6.5 inches of water. I haven't changed anything other than adding biopellets over 6 months ago. The skimmer will skim perfectly for a week or more and then randomly overflow instantly. Just an hour ago I checked it before making breakfast, the cup was nearly empty. Then instantly while I was eating it overflowed.

