Ok, I have an alpha 170, i posted probably 4 or 5 months ago when i first got this skimmer. I had the surging issues that i really never i got rid of. No matter where I had the nozzle is still had the surging. In fact I've gotten so frustrated I'm on the verge of selling it. I could never really get it fine tuned becuase of the small sump it was in, no room to get the hand in. I ran this skimmer in 8.5" of water. Now onto the move, I'm upgrading from my 58g to a 120g in a few weeks (i know the skimmer is way to much for the 58g but I got a deal on it). I pulled the skimmer from the 58g because is was nothing more then a sludge maker in the neck. I cleaned it and put it in its new home, nice large extreme octopus sump. I started my leak testing today, of course with the skimmer in the sump

I fired it up to keep the water moving, tons of bubble in the sump. I'm assuming that will go away once it is slimmed up again. But I started playing with the volute. I closed it completely, made a mark at the 12 o' clock position. I then backed it out 2 1/2 turns (seems to be the common consensus that 2 turns out would get me in the ball park). I could hear the surging, it wasn't a lot, but enough to notice, plus the water in the body was moving up and down a little. I moved that volute from totally screwed in to almost completely out, still got surging. It would slow down so you could barely notice to it was so rapid it was a surge a second. So completely frustrated I pulled the volute all the way out, the surging went away and the amount of bubbles were insane. The water level in the skimmer body is about 2" below where the collection cup screws in. I must still have some vinegar left on the skimmer body. The volute has a number on it, #74 written in marker. I'm at a complete loss on what to do.