3 fx5s (Overkill) on a 220 and sick of microbubbles ?
1. setup your fx5's properly and microbubbles won't happen unless your filter is clogged up and time to clean !
2. Don't over stock your tank and try to compensate with filtration !
3. Thinking about going to an eheim is taking a step backwards ! My experience in over 20 years of using eheim products, they make great pumps, and the old filters were pretty solid, pitty about the rest of the filters especially the ones released in the last 10 years or so.
4. If you want less maintenance and somewhere for your heater then a sump set up would be more efficient and hold way more bio than any canister ? You could eliminate 2 of your fx5's off your setup that way.