I think both AC110 and Emperor are overpriced, bad filters. AC is vulnerable to leak at the O ring as cleaning the impeller requires removal of the motor and over time the O ring wlll wear out and fail. Another leak vulnerability is when the sponge gets clogged up and popped up, dripping from the top. Marineland Emperor has a complex double impeller blade design to drive the spray bar and biowheels. The added complexity only makes Emperor less reliable to restart.
Marineland's Penquen filters are simpler, cheaper and restart more reliably than Emperor line filters. I am running a dozen Penquen 350 and 170 in my tanks, some amazingley for more than 20 years and are still working. The only maintenance I need is to replace the impellers after 7 to 8 years when it starts to get wear out and make clicking noise. As for the filter media, I bought polyester battling form JoAnne fabric by the yards and cut it up, costing less than 10c per double pads. BTW, I run all my Penquins without the biowheels as I don't think they are needed even though they are perfectly functional. I use my HOBs for mechanical filtration only as I believe there are plenty of beneficial bacteria already in the substrate, ornament and glass surfaces inside my tanks.
Marineland's Penquen filters are simpler, cheaper and restart more reliably than Emperor line filters. I am running a dozen Penquen 350 and 170 in my tanks, some amazingley for more than 20 years and are still working. The only maintenance I need is to replace the impellers after 7 to 8 years when it starts to get wear out and make clicking noise. As for the filter media, I bought polyester battling form JoAnne fabric by the yards and cut it up, costing less than 10c per double pads. BTW, I run all my Penquins without the biowheels as I don't think they are needed even though they are perfectly functional. I use my HOBs for mechanical filtration only as I believe there are plenty of beneficial bacteria already in the substrate, ornament and glass surfaces inside my tanks.