Fluval 103 Multi Filter
390 Liters per Hour (103 gph)
Fluval 203 Multi Filter
420 Liters per Hour (111 gph)
Fluval 303 Multi Filter
840 Liters per Hour (222 gph)
Fluval 403 Multi Filter
1200 Liters per Hour (317 gph)
Hagen - Fluval Series 3 Canister Filters
When I bought my first Fluval I was thoroughly impressed with my water quality. I was running 2 180 L tanks, one on a Fluval 303. The other on an undergravel system with 2 power heads. The water comparison was like apple juice to water. It was incredible. I went out and bought another right away. As far as the O-RING goes, my guess is that it likes to roll itself back up when you let go. I had the same problem. Don't roll it on, that's the trick. Put it around one side and stretch it over without rolling it on. This way it will not be able to roll off. I hope you all will enjoy your Fluvals a bit more now. They really are worth investing in.
I have had a Fluval 103 and a 403 running continuously now for the past 8 years. I have never had a problem with either of them in any way, period. As was already posted, if you read the instructions and take a bit of care, the o-ring is not a big deal at all. I have never had a leak. I have been an aquarium hobbyist pretty continuously for the past 35 years, and have tried just about every type of filter imaginable. The Fluval has an excellent flow rate and when used with a bacteria supplement such as Cycle, provides excellent biological filtration and very good mechanical filtration. I perform filter maintenance on a 3 month schedule, and I only replace a portion of the media at each cleaning. As far as I am concerned, the Fluval is hands down the most cost-effective and most reliable filter that I have ever owned. Easily a 9 out of 10.
I have used a Fluval 304 on a freshwater 160 litre tank for twelve months. It has been very successful, and keeps the water sparkling clean. Most of the problems I read about seem to be caused by incorrectly setting up the Fluval, or not understanding how it works. The primer plunger should need pumping only once or twice, but will not work if the ball valve is not installed on the bottom pipe of the tank outlet. The pipes will leak if the threaded nuts are not screwed on to the outlets first, and then back screwed to clamp the hoses. The blue side clamps are overcentre locks. The claws must first be located under the lip of the barrel, and then the levers pulled up to pull the motor housing down on the barrel. It won't leak if this is done. The instructions are all there, it just takes patience to read them all.
I have used a Fluval 304 since 1990. I once left it running on my tank when I moved out of my Dad's house, and did not go back and even touch the filter for over a year. Filter was still running fine (one large oscar, and one monster Pleco in a 115 L). I admit that was not responsible maintenance, however the filter was still running as strong as ever. I never had a leak, and took care to use Olive Oil on the O-ring, so the same one lasted me more than a decade. I eventually gave the filter to a friend after more than 10 years of faithful service, and for all I know it is still running strong. Just last year I purchased a new model Fluval 404. I sorta miss the old design, but this one is serving me faithfully, and has a couple of new things: self priming, hoses mount to gizmo that has a water cutoff lever, and a quick release. This new filter has the appearance of another faithful filter, and yes, I do routinely clean and maintain it every 3 months or so, and will not be testing the annual maintenance theory any more. This model does a good job on my 340 L Cichlid tank, along with a powerhead. I'm thinking of buying a second filter, as African lake cichlids really do require a lot more filtration, and I want to alternate filters when cleaning, one every other month, to keep bacteria growth in at least one filter at a time.
I have been an aquarium hobbyist since 1989 and I am now 31 years old. I tried Marineland hang-on power filters back in that old-age technology era. Back then, I thought they worked great, despite their early back-up's due to clogged cartridges. Fluvals, AHHH, solved the problem quickly, because they've got those filter bag capabilities, no more bypass problems. They filter water great, and the media compatibilities are endless as long as they will fit in the canister. A GREAT filter for no-bypass filtration. The only drawback is, I would suggest at least an airstone in your tank from an air pump that plugs into the wall, plus a battery operated air pump to keep your fish alive if a storm dumps your electric services for a period of time. Otherwise, Fluvals outweigh hang-on power filters TREMEDOUSLY, and cheaper to maintain with filter media bags than having to buy cartridges that are disposable (what a waste!).
These pages have enough comments to give the reader a basic idea on the topic. Further comments are still very welcome (through the site's contact form) as long as they provide new and/or advanced information not yet discussed in the existing ones.