When I was looking for a different filter than my traditional HOB type filter the Marineland HOT filter was on my list. After researching about I decided against it personally. I will agree that the HOT filter is well made, but I decided to go with an under the tank cannister filter instead. If you are worried about maintenance I have found that the Fluval 404 filter I purchased is fairly easy to work with. You mention that you are looking at the pro system which has bio wheels. I'm guessing like me you were worried about bio-filtration. I was also, but since my filter has 4 levels I loaded the bottom with filter floss, next is a carbon layer, and the last 2 levels are currently filled with biomax media for biological filtration. I'm much happier with this filter than the Penguin 330 filter I replaced and my tank is just as stable with zero readings on ammonia and nitrites just as before. This is my first canister filter, but I don't believe it will be my last.
