Ive been running the Tunze osmolator for months without issue. About a week ago, the water got really low before I noticed it. Filled it up, but ever since then, while it‘s still pumping water, it also pumps about a million air bubbles into the tank every time it runs. I’ve tried turning the pump upside down while submerged, shaking it, etc, to remove any air from within the pump, but that hasn‘t fixed the issues. Any other suggestions?