Ive had this skimmer for about 3 months now running in a holding tank at about 5-6 inches of water and its ran fine. The main tank finally cycled so I cleaned the skimmer, put it all back together and moved it to my sump of the display tank which is about 8.5 inches of water. All this thing does is filled with bubble water and overflow. I have the valve all the way open and ive tried moving the main tube around to see if that will help. I dont know what else to try and do except for raising the skimmer up onto a stand