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
I have had the 403 for about seven years. It works great and I have not had any down time. The only tricky thing is to be certain the O-ring is in its proper place when sealing the unit, or else water will run out of the canister. One improvement could be a better return tube that was one piece. Overall I would give it an 8 out of 10.
We must have a lemon as the motor is shot after about a year and a half of use. When it is running it is great. Cleaning it and putting back together is a pain. I'd rank it like 3 out of 10.
I agree that in general fluvals are good filters. They are difficult to clean (in common with most canister filters), though, and I have found that on deep tanks they are really not powerful enough to lift water. I have a 403 on an 80 gal xh, with a uv sterilizer, and have to use a separate external pump to get decent filtration.
I recently bought a Fluval 1 (pumps 50 gph) for my 5 gallon hex tank because it was the smallest filter the store had and came highly recommended by the salesperson. I'm a beginner to this hobby, so I don't know much about quality of filtration and such, but I know one thing-- this filter is POWERFUL. Too powerful in fact. It says on the box that it is for all aquariums up to 10 gallons, but I think it'd still be too powerful for a 10 gallon tank. There is no knob on it to control the rate at which the water is expelled from the device. As such, I am stuck with a current that causes my plants to become uprooted and buffets my snails about to the point where I don't even turn it on any more (the tank was initially bought to house aquatic snails). The fish seem to love it, as it creates lots of bubbles for them to chase, but even so, I would think that if left on for a lengthy period of time, the excessive current would tire them out. It seems like a good filter, but not for small tanks as it is advertised for (the box says "fits inside any aquarium").
I have used Fluvals over the years and had some success..The 'O' ring can be a little tricky sometimes, and with the change to the grey canister being able to actually see if the 'O' ring is properly placed, is difficult...you don't know until you fill it back up and the water starts leaking out all over the place...I tend to use a bit of Vaseline and watch very closely when I replace the head....Eheim makes the absolute best filters on the market, but the Series 3 Fluvals are a very close second...Fluval 103 was my first canister, 30 years ago, I still have it and use it once in a while when I need to use carbon..this thing is still running and has never needed a part, ever. Most people seem to clean out their canister filters far, far too often...every six to eight months is really all that is needed unless you are rwally overfeeding the tank.
I have had experience with Fluvals over the last 5 years. I have used the "3" series and the newer "4" series. I would recommend them to anyone wanting a cannister filter with a moderate bio-load, up to a 100 gallon tank. I have used the 303 and 403 quite a lot, and while they are not as convenient to clean as a box filter, they are comparable to most cannister filters. The new 404 is even easier; with both filters, once you overcome the learning curve, they are easy to work with. I really like the quiet of the Fluval, which is a little quieter than most Eheims and definitely much quieter than the Magnum, as long as you replace the impeller when it gets "noisy" after about 2 years. What I really love about the 3 series fluval is the almost infinite choices of media with the round baskets. I have used 5 or 6 different kinds of "biofilter" media in my various fluvals, all types of resins and pouches, pantyhose filled with carbon, sponges, plastic media, peat moss - they all work great. I would rate them a 9 out of 10.