Originally Posted by mistersprinkles
You can get crystal clear water with a $6 sponge filter. Canister filters in general are not good at water polishing.
The reason canisters have a lower flow rate vs their size compared to HOBs is to allow a longer contact time between the water and the biological media. A little Aquaclear 110 has a higher flow rate than almost every canister filter out there.
While it is true that a sponge filter can achieve crystal clear water, I disagree about canisters not being good at polishing. Canister filters generally have room for more filter media, which allows water polishing. A sponge filter wouldn't be as good at polishing because it has a very low flow rate, which means debris won't get sucked in and trapped.