Does anyone have a remedy to get these too stick/stay put on the glass? I wiped the glass area where I'm putting the pumps with vinegar. I let it dry. Put the black rubber circle on to the tank. It wouldn't stick like I see in the videos. I hold it with my hand and place the wet side into the tank to where I beleive it will connect with the dry side, plug it up and the wet side falls to the bottom. Measured the glass thickness on the sides and its 1/2 inch thick. Still didn't work. Tried moving the dial to 5/8 on the dry side and no luck. Any suggestions?