I am relatively new to saltwater, and was lucky enough to get a ConeS CO-1 several months ago for my first system (a 72 gallon FOWLR with a 20 gallon sump). I purchased this skimmer primarily based on the great reviews I read here. I have a relatively light bio-load (3” hippo tang, 2 B/W clowns, and a green chromis plus clean-up crew of hermit crabs, snails, and peppermint shrimp)
I have had a hard time adjusting it to consistently produce good skimate. It either produces minimal skimate, or has a serious overflow problem. If I adjust the foam level, it will run fine for up to several days, then either start to overflow or the top of the foam level will drop a couple of inches so that only the underside of the angled collection plate collects 'gunk' on the foam side, with no liquid skimate making it through the plate into the collection cup. When I first installed it (back in January) I was doing hyposalinity treatment for ich, and based on reasearching this site I knew that skimmers don't work well under these conditions, so wasn't surprised I was having trouble tuning it.
When I brought the system back to 1.025 SG I continued to have problems. I don't have an ATO system (yet) but I didn't let the water level drop more than a 1/4" before topping off, but continued to have problems tuning.
I thought the problem might be that I was shutting both my return pump and skimmer off during feeding time (please no flaming!) and a slightly fluctuating water level. Subsequently, I have put the skimmer in a plastic box in my sump and I leave it running 24/7 with a constant water level even when I shut off the return pump.
This week was typical. When I left to travel for work on Sunday, the skimmer was set for the foam to slightly break just below the hole on the collection plate. My wife was feeding the fish for me, and Monday night she said everything seemed fine, with maybe ¼” of weak tea colored skimate. When I returned Tuesday night, the collection cup was full, and lid had scum on it, indicating it had seriously over-flowed. I drained the cup, and continued to drain it while the skimmer continued to dump foamy water through the collection plate. Thinking it may be a slug of stuff that had to clear, I continued to drain the cup (which filled in about 2 minutes) but even after collecting a ½-gallon of water of clear water, the overflow did not slow down. To get the level on the skimmer right so it wasn’t overflowing, I had to turn the adjustment valve about a quarter turn. That set the top of the foam level to just below the hole in the collection plate so it wasn’t dumping water into the cup.
Now, several days later, the top of the foam is only near the bottom of the collection cup, and no skimate is being collected, with gunk coating the top of the collection plate underside and the bubbles break far below the hole in the collection plate. I know if I adjust the foam level now, within several days (or sometimes hours) it will go into serious overflow mode, as it has repeated this pattern many times. Small increments on the adjustment screw (1/16 turn or less) noticeably change the top foam level.
Right now it is in 8” of water (up to the bottom of the silencer). I tried 7.5” and was no better. I tried 8-1/2” and also had the same problem, plus the silencer would get water in it. I’ve tried cleaning the collection plate cup between adjustments and leaving the gunk there, only draining the cup. Same issue. Anyone have a similar problem keeping it adjusted? Is there a solution to get it to skim consistently without constant adjustment?
