The skimmers work wonderfully and are not hit and miss. Too often we are guilty of making way too many adjustments in a short amount of time - a day or two, because the cup isn't full of black nog.
Snafu- Set the skimmer in 8" sump depth, turn the nozzle to 3 turns out, and set the water level inside the skimmer to approximately 1" below the bottom of the collection cup, or at the highest at the bottom of the collection cup and walk away from it. Come back to the skimmer in 1 day and let me know what it's doing. Do not make any adjustments what so ever to the skimmer in a week and let me know what happens if it has a nice foam head built in that first day or two.
Greg45- You have an Alpha 250? How many gallons is this system on? How old is this system? Stock load? Give me more details on all of that. For your setup, put the skimmer in the sump of 9.5" sump depth. Turn the nozzle 3 turns out, and set the water level right at the bottom of the collection cup inside the skimmer. Walk away from it for a full day or two, and do not make any adjustments within 3-4 days or so, let me know what happens.
Guys, I can't stress enough to stop making adjustments on your skimmer multiple times a day. Just set it and walk away for a while.
Thanks,
Jeremy