Fluval U3 Internal Filter

I have just replaced an old filter with this Fluval U3 for my 90L tank having lost lots of fish over recent weeks and struggling with water quality. It is early days but since replacing it, the water quality has improved and it looks much clearer. It was a little noisy to begin with but soon quietened down. Opening the various compartments to prepare it was a bit stiff to begin with (and the instructions not very clear for this) and I was worried I'd break it but it seems fairly sturdy and I'm sure it'll become more supple with use. The replacements also seem good value. (Posted on 02/03/2013)

this is one of many filters I have purchased over 18 years of keeping and breeding tropical fish, in summary, the best I have ever known, does exactly what is required and keeps water crystal clear, filters are reasonably priced and easy to purchase from many stockists, I would really recommend this product, one negative and one which I am trying to solve at present is the bracket which holds the filter to the tank wall, mine is broken and I cant seem to find a replacement, this however is after many years of use so dont be put off, if I have to I will happily purchase another filter unit, well worth it. (Posted on 07/02/2013)

The Fluval U3 internal filter came as part of the package when I bought my Fluval Roma 125 Aquarium. An exceptional product for its price,having had this running for around 3 years now, it has proven extremely reliable and easily maintainable,having just decided to upgrade to the U4 I have also ordered spares for my U3 as I will continue to use it in another of my Tanks,the easy availability of all the spares as well as its life expectancy and reliability makes this Brand second to non for Me.
(Posted on 06/01/2013)

These Fluval filters are just simply the best on the market. You couldn't buy better for this fantastic price! And dont worry about noise; my fish make more noise than this filter! Would always recommend. (Posted on 03/12/2012)

after months of research i decided that this filter would be my best option without braking the bank or delving into the unknown of external filtration. my water is always clear and free of debris and the media change is a doddle, pull the filter forward (it tilts) open the top and pull each cartridge out and change, simples. the other clever thing is the flow of water, it has three settings so i can have the flow coming out the top to make the water ripple, one long multi directional bar in the middle which is gental for planted aquariums and one for the middle to bottom which i use for circulation. efficent, easy and it seems very durable. great product (Posted on 21/11/2012)

A good filter overall, probably the best internal after the aquaball series.
This filter is amazing at doing its job, but.... it is a very bulky piece of equipment and the media compartment is intentionally not ergonomic. I say intentionally because Fluval wants us to buy their pricy filter media kits, when all this space could have been used better with after market media.
Concluding, if you don't mind the bulkiness and you can live with the media problems, this is a very efficient filter that will manage to biologically and mechanically maintain a tank of 100-120L easily. (Posted on 19/11/2012)

As the title says a great sturdy filter, received as a subscription gift with pfk magazine but would easily buy from the range again. The filter allows for 3 methods of filtration but what impressed me was the amount of bio material you can get in the cage inside the filter body. another main point is the ease of cleaning and flow adjustment cleaning the filter is a doddle open the top flap and you have quick access to all filter types witch can be found d at reasonable prices. I regarding flow adjustment you can choose from 3 enabling fast agitation or smooth slow stream like water movement all in all a great bit of kit!!! (Posted on 07/11/2012)

Have always used Fluval internal filters as i have always found them the most user friendly and easiest to get replacement media for. This new range is no exception and I love the fact you can now alter the water flow and it works brilliant with excellent flow and oxygenation. Make sure you use it with a 30" plus tank as the output is too much for anything smaller and would blast the fish around. (Posted on 22/05/2012)

Solid construction and a very well thought out design. The flip top access to the cartridge based filter media is simplify brilliant. I always used to dead filter cleans, needing to remove the entire filter was always messy, now I can flip open the top and switch out the media. Even better as I can alternate between each side. Filter is extremely effective and keeps mybtank clean where previously 2 filters were struggling. Anyone considering a new internal filter should get one of the U series filters from Fluval, you will not be disappointed. (Posted on 21/05/2012)

This filter is great and was very effective as soon as i put it in my tank. Preferred to larger tanks due to the size but is a must buy when in need of a filter. Rapid delivery. (Posted on 15/05/2012)

Originally saw these in Practical Fishkeeping mag and thought they looked good but were too expensive. Got one as a subscription gift and I'm a convert. They are so well designed to come appart to get to all gungy bits and re-seal. Replacement pads are sold everywhere. Solid casing lasts through all the wear and tear. Flow adjustment so all water comes out of top, bottom or length of filter to suit different fishs' requirement. Neat. i don't buy any other make now. (Posted on 03/11/2011)