An update to the pulsing that my 170 is doing with the adjustable nozzle. I received a new pinwheel, shaft and rotor setup because the other one I could turn the shaft in the rotor (took a lot of pressure but still turned) Pro L thought that was the answer, NOT. Same thing runs great with nozzle turned almost all the way out to completely out. Talk to a PL rep who told me that he didn't see a problem because you want to run more more air in the skimmer without excessive micro bubbles. Then went off into scientific reasons off high different altitudes and pressure affect skimmers in different areas. First off the pump ran fine for almost three months. Give it a freshwater bath and whamo, pulsation. Now they say if is perfectly normal to run this without the nozzle, then why put the nozzle on it? Here I am trying to sell it which is now a problem( try telling the buyer, oh you don't need the nozzle that was put on as a preference because our customers wanted to have another adjustment on the skimmer) yea right. Does anyone else have this problem? If not I must be living in the wrong scientific region for this to work. Guess someone doesn't want to honor there warranty and swap this out for one that works properly. Very dissatisfied owner of a Royal Exclusive product. Sure hope I don't have any problems with the Mini 180 I purchased recently. Does it sound like I'm pis#@d, you betcha. And I didn't buy this from PA so don't think I am in no way downing them, quite the opposite since they have helped me in the past, just thought I vent here in this forum. Anyway I am not through with this yet and Pro L.