Since everyone has had positive attitudes about canisters.
I will state my opposite opinion.
I believe they are no better than HOB filters, in fact I think they are worse, because they are "not" user friendly to clean, and fall apart when regular cleaned, so in general will sit and run for long periods of time, becoming nitrate and pathogenic bacteria factories. (bacteria love gunk, and unless rinsed regularly, they fill with smelly gunk, spewing invisible toxic compounds back in the tank, and which is "not" good for beneficial bacteria
I gave them up years ago for sumps, or back to HOBs because I found there is nothing magic about a pressurized can.
I will state my opposite opinion.
I believe they are no better than HOB filters, in fact I think they are worse, because they are "not" user friendly to clean, and fall apart when regular cleaned, so in general will sit and run for long periods of time, becoming nitrate and pathogenic bacteria factories. (bacteria love gunk, and unless rinsed regularly, they fill with smelly gunk, spewing invisible toxic compounds back in the tank, and which is "not" good for beneficial bacteria
I gave them up years ago for sumps, or back to HOBs because I found there is nothing magic about a pressurized can.