I purchase one of them long acrylic feeding pipettes with a blue bulb at the end for the purpose of feeding corals and as well removing any waste/material from the sand bed. However, for the latter purpose, the product doesn't work because when I suck up material up into the pipette, and when I release the bulb, the material goes back down the tube and into the water. I could remain pressing on the bulb up top, but that's not the most practical.
Am I missing something here?
Am I missing something here?

