TLDR: Filter that actually works??? Anyone?

Can anyone suggest a workable filter for a bullfrog tank? Currently using an aquatech filter that takes 10 minutes to finish priming usually. Swapped out 90% of the water as the bullfrogs (5 juvenile size in a 40G breeder with custom elevated land area) tend to make a mess of it. When I refilled and plugged the filter back in it absolutely refused to prime. Over 20 minutes of pouring water into it. Sometimes a steady trickle, sometimes a strong waterfall. The thing has been running for over an hour now casually stirring the water inside it instead of pumping it. It's not making any funny noises, there are no air bubbles. It sounds like it usually does (minus the trickling water, which I attempted to fix with an elaborate plexiglass/pvc return box but apparently plexiglass does NOT like a hole saw). Add this to the frustration of having the same problem on another aquatech straight out of the box and a tetra whisper-whatever that wouldn't even turn on when plugged in. I'm getting tired of returning these things. I have another aquatech unit in the firebellied toad enclosure, but I have a feeling it's going to do the same **** to me when I change their water...