I was doing a water change the other day, and with the tank about half empty I went to scrub some algae off the input tube. I dislodged the tube from the suction cup, and for 1-2 seconds it turned horizontal / out of water (sucked up air) ever since then, I have about 1/3 flow from the filter. I tried turning it off and on, and priming it again. I left it off and primed it 10-15x to try to force any air out etc. Any ideas?