Fluval FX4 High Performance Aquarium Filter, Canister Filter for Aquariums up to 250 Gal.

I have kept fish for about 50 years. I have experimented with many aspects of the hobby, studied everything, and done trail and error. Now I just run one 150 gallon tank, but at times have had many. I also have out door ponds. What I know is that most crap you read from so called experts on the web are "crap". After 50 years the basics are the same. The equipment has improved. Most people have no clue as to what a filter can do or should do. Go to my forum at yardcraphome dot com and open the critters section. I hooked this fx4 in today. I have been running the older fx5 (new model is fx6) for years and consider it a good buy. The fx5 had some challenges as to leaks and easy to break clamps, but suspect/hope they improved with the fx6/fx4 update. The fx5 is very good, best filter I have owned. Flow rate is important, but also is volume. These fx6/fx4 are huge. If you just want flow, buy a circulation pump. What you want is the water to pass over lots of helpful things before returning to the tank. I use multiple filters for different things as that helps as to maintenance. . One (fx5) is mainly for biological which is by far the most important. Due to the great 900 gal output, have it hooked to a a Tetra Pond bio filter that they claim handles 4000gal (doubt that). That reduces flow rate, but the combination is over kill for biological in my tank. The two together are like a large, but closed sump filter which can hold lots of bio material. The now dead Fluval 300 (or something?) was for chemical and needed replacement. I looked at filters to replace it and almost went with the new Ehiem 600 (great filters), but in the end got the small brother of the large Fluval that is still working great after years. I decided on the fx4 as opposed to the fx6 due to the fact the volume was enough when just for chemical, and I don't want my tank to become a rushing river. One thing with these is adjusting flow rate is very easy so maybe should have gone with the fx6. I hooked it up today and the only problem was a leak at the input connection. I wrapped some Teflon tape and easy fix. I filled it with Chemi-pure (because I have used it for decades) and and Purigen (which is just an excellent product). The flow rate is not that much more and my fish friends are large fish. I don't think flow reduction will be needed. My opinion is that for many, the fx4/fx6 is a best buy. The down side is they are large. Large is also the good part, but maintenance must be done from time to time so keep that in mind. These are heavy. I have a small room with a sink where filters live and tubes pass through the wall, so easy for me. My 3rd filter is the Fluval G6 which is a joke. This would be good for a nerd type with a small tank with low fish levels. I only keep it hooked in for the mechanical cartridge (no where near as good as the older Magnums, but very easy to service). Mechanical filtration occurs with all filters and while nice, should not be the focus of your filter choices.

Works great very durable and really pumps water through. Set up was a bit much but not more than any other large canister filters I would assume. Very customizable for your tank and outlet setup. Price is also a bit high compared to competitors but I definitely feel the quality is there. In reality if you bought a 200 gallon fish tank $300 for this filter shouldn’t be out of your budget and definitely can’t go wrong with this purchase.

So, it's only day one of having my tank filled and filter running, but that's all I needed to have enough information to write an initial review. Why? Three reasons. I'll start with the easiest...as with my experience with the Fluval 306 in the past, the FX4 is extremely quiet, which is an absolute must!!! Second, the filter is extremely easy to set up. Finally, because I don't have any standard faucets where I can use a hose adapter, I tried a couple other ways to fill my tank...both of which failed. I finally decided I would just carry buckets of water over to the filter and try out the pump function of the FX4 and HOLY MOLY, what a life saver!!! Yes, with a 120 gallon tank, it took 20+ trips from my kitchen sink to the aquarium (I'm going to figure out a simpler plan for water changes that's for sure :) ), but the pump function work flawlessly and vwalla, tank filled! Fluval has never let me down. This is the third filter of theirs that I have used... I definitely recommend them to anyone trying to decide which one to use.

You can’t beat this Product really a powerhouse of a pump. Using this on a 75gal Reef Tank. I tried a sump just could never get it adjusted correctly. My water is crystal clear

I bought this product July of 2020 it was working great until May/June of 2021. I bought the 3 year warranty with this product and contacted Fluval when it started to mess up. I cleaned the filter out and all the hosing and it still would not work. It would not even make a noise like it was trying to start anymore. Fluval emailed me back and wanted me to clean out where the motor is. I did this and it still was not working so I emailed them again and then they stated they wanted pictures of the clean filter so i had to do this as well and send it. Then they decided they wanted pictures of the entire set up. Basically every time i talked to them they came up with more excuses as to why it wasn't working properly. I followed the instructions verbatim when setting this filter up and like i said it worked great for over 9 months. Each email they sent had a different excuse as to why it was not working. I even took the motor area apart and took a video of it plugged in making a noise like it wanted to work but not rotating properly. As this point i am getting very agitated. I paid around $300 for this filter and the 3 year warranty and they are refusing to uphold their end of the deal with the warranty. This has been over a month now that i have been emailing them trying to do everything they say and my turtle is struggling without filter and they have done everything they can to make it difficult and to make up excuses as to why they aren't honoring their warranty. I have never written a bad review but this is very frustrating and costing me a lot of money that i do not have. The whole reason i purchased the fluval was because of the warranty and the fact they aren't honoring that is infuriating to me. So if you are thinking about purchasing their products keep in mind they won't honor their warranty .

Omg, it's the best thing that could happen to me. Quiet, strong motor keeps the tank sparkly.

Great canister filyer and super durable and easy to clean. Puts out good water fliw and lasts many weeks without a worry to clean.

Şu ana kadar aldığım en iyi dış filtre parasını hak ediyor

Good product, good price and fast delivery.

Snabbt smidigt

ممتاز وكل شي تمام وتمشي مع كهربة السعودية والفيش جيبوله راس ينحل موضوعه بس الغطا يعل بتقفيلته لانه لف مسامير اقل غلطة تسريب

I bought this filter after my old one gave up. I gotta say, this was one worthy investment. It’s great! Easy to assemble and clean. The valves are positioned great. Noise is minimal and suction power is good, keeps my tank clean at all times. Never had an issue since installation. Highly recommended for large fish tanks (I have a 90 gallon tank)