Filter suction cups not suction-cup-ing...
I have a Duetto that suction cups on to the side of my tank... great filter, except that at least every other day I have to stick it back on.
Minor problem because every so often I shoo several almost-dead tetras out from behind it when it comes un-stuck at the top and not the bottom.
Suggestions? So far I have been able to limit too many issues by having my Mag-Float sit underneath it to support it, but the top still comes unstuck every couple of days.