Thanks for that post Dennis! :thumbsup
my cs220 is hob and I replaced the orig tube with one that placed my powerhead about as close to the bottom of my tank as possible. I was assuming this would add pressure but make things such that water level would affect pressure relatively less. WRONG! I wonder if I should shorten the tube.
{Try a new new piece of tube and shorten it so your pump is 2" below the surface of the water. Make sure the airline nipple is pointing upwards, too. Your pump is fighting air pressure way down there. Also, make sure you clean said nipple on a monthly basis. Buildup will get in there and suffocate any air trying to get into your needle wheel pump.}
I have gotten rid of the bubble diffuser for now...
{I don't use mine either, but my skimmer is in a sump 20' behind a wall. I have not found it to degrade air intake so long is it's dry.}
as I would live with micro bubbles if it meant a better skim.
{I can't see how that would effect it, but I suppose anything's possible}
I have my collection cup emptying through 1/2 inch to a 2.5 gal container (cause it overflows once in a while)
{I do the same, because I don't like emptying it all the time}
. I have an air pump set up on some valves and pumping air into the air intake on the input side of the powerhead. I don't really use this all the time... just once in a while when I stop getting air bubbles I get it started again with a little pressure.
{You should not need this once you raise the pump close to the waters surface.}
I also have 3" of air tube off the output side where there is a nipple - to redirect any output back to the tank.
{This makes me think there's too much flow or the hose is plugged somewhere, not a normal thing from my experience}
Other than that my skimmer is stock outta the box.
I don't have consistent top off being added... I add it in whenever possible.
But where I noticed the biggest overflow prob was when I added microvert.
The flow adjustment seems to be impossible to master. Either too high or too low. Any ideas? {heck yes, my only complaint with the skimmer! What I did to remedy this; take a 1x2" piece of wood, say 8" long. Cut a notch in the wood to fit over your adjustment on the skimmer. Precision at last!}
thansk {my pleasure, I hope it helps! }
One last thing I'd ask you to check is when you add your topoff water pay attention to how fast your collection cup starts to fill up. Changes in the water level will effect the skimmer and you may need to throttle it, depending on how much the water level changes.