Fred......if you are taliking about rigging a powerhead or aqualifter to the u-tube, how do I do it? Another question......how many u-tubes can you have on one overflow? I have a Quiet One 4000 (1017 GPH @ 0' Head), and it's turned almost all the way off. The overflow has two 1" outlets. I have 1 u-tube running now, as my other one seems to be too short to reach correctly. Thanks in advance.