Hagen Fluval U2 Underwater Filter

There are many choices out there when it comes to filtration for your fish tank. Which of the many choices out there would make the best choice for you? Internal, or external? Are you looking for supplemental filtration, or primary filtration? In most situations, an external filter would be the better choice. Canister, power filter, wet/dry sump, refugium, all have the advantage of not taking up any space inside the fish tank. They are also all capable of holding more media than internal filters. However, some situations make it difficult to install an external filter on a fish tank. For example, if the tank is located in such a way that there are no available spaces behind, nor at the bottom, then your only choice might be to use an internal filter. For simple biological filtration, an air-driven sponge filter would suffice. However, a pump-driven internal filter offers increased circulation and better mechanical filtration. Let us say that you want an internal filter that is capable of providing complete filtration. Not just supplemental filtration but rather a single filter that can provide mechanical, biological, and chemical filtration. In that case, your choices will be limited. Most internal filters are designed to provide supplemental filtration. Most will provide mechanical and biological, but few of the designs will provide chemical filtration. The Fluval U-series of internal filters provide complete filtration, with the exception of the smallest model in the line up. This is the best internal filter that I have ever bought. An internal filter would not be my first choice. However, I was faced with a situation that would not have allowed the use of an external power filter. My choice then came down to between an internal vs. a canister filter. The tank will contain floating plants. Circulation needed to be gentle, and the surface of the water should be still. This filter met the requirements, without the maintenance hassle of having to use a canister filter. The filter was easy to install. The bracket system allows you to remove the filter, without having to remove the suction cups. The suction cups are attached to the bracket, and it is the bracket that holds the filter unit inside the tank. It is surprisingly quiet. You can adjust the output. Water can exit from the top, the middle, or the bottom of the unit. The middle output provides the most gentle flow. Mechanical filtration is provided by a coarse sponge, followed by a fine filter pad. The back of the filter pad is carbonized. This provides a little bit of chemical filtration. Biomax ceramic rings provide the biological portion of the filtration. All in all, a tidy, complete filter system. Disadvantages? It takes up a lot of space inside the tank. The small amount of carbon bonded to the filter pad is not enough to remove tannins from the water. And, it gets used up very quickly. It is possible that you may be able to remove the biomax and put pelleted carbon in its place. Another weakness is that the mounting bracket uses suction cups to attach to the tank wall. A truly modern filter design such as this should be using magnets instead of rubber cups. If you can use an external filter, that should be your first choice. They provide advantages at all three types of filtration (mechanical, biological, and chemical) over even the best internal filter out there. However, if you must have an internal filter, then this is the one that I would recommend. Any of the Fluval U-series, starting with the U2, all the way to the U4 will provide complete filtration. The smallest model, the U1, will not provide complete filtration. Highly recommended. This could be the best internal filter system available in the hobby, in the humble opinion of this reviewer. Please know that I do not own every model of internal filters out there. I am basing this on the ones that I have owned over the years, but there are a few models that I have not tried. However, I have researched the ones commonly available in the U.S., and this line appears to be the best out there. Consider your needs carefully before you decide. If ever Fluval were to discontinue this model, then you will find it difficult to find replacement media. It is not as easy to "create" your own media for this as it would be for an Aquaclear. But it can be done. You can buy bulk padding and cut them to the approximate size and shape of the plastic holder. For carbon, you can simply replace the biomax with large, pelleted carbon.

The Fluval 2 Water Filter is designed to work in a variety of configurations. This makes it absolutely perfect for tadpole tanks. You can put it sideways, just beneath the surface of the water. This creates a long "basking area" that the tadpoles absolutely love, while at the same time keeping their tank clean. I had no idea the Water Filter would be so ideal when I bought it. Sure, I knew it had a great reputation as a water filter, and that it could create a gentle stream. That is of course the big challenge with tadpole tanks. Tadpoles are MESSY - but they are also tiny and delicate. You want a filter that moves enormous amounts of water in order to keep the tank clean. At the same time, you don't want industrial-strength jets of water blasting into their swimming area. Especially when tadpoles are just developing their little arms and legs, getting hit with that water blast could cause all sorts of damage. The Fluval 2 Water Filter is very easy to set up. You decide what kind of output stream you want, set the speed, and voila. You stick the whole thing into your tank and you're set. I put it in sideways figuring it would take up the least amount of swimming space that way. I was completely shocked when I came back a few hours later and found six of the little tadpoles had wriggled their way on top of it and were soundly sleeping there. At first, I was worried. Would a little limb get stuck somewhere? Would the soft buzzing bother them? But no, it almost seemed soothing. They actively wrestle with each other to get onto that spot and, even if others come and pile on top of them, they lay there contented. It is really cute to watch them. They're like a pile of kittens. The water in the tank is absolutely much cleaner with this running. It does the best one could hope for against the output of these industrious little baby frogs. Highly recommended for tadpoles. Just install it sideways, just below the surface, so the little tadpoles can rest on top of it. There's lots of photos and videos of this in action all through the SuttonMass site. Ask if you have any questions!

Not going to write a lengthy review. I'm just going to point out the reasons why I changed my rating from 5 stars to 1. -Filter only sucks in debris at the top half of the unit. A lot of debris just floats by the filter without getting sucked up. Weak suction. -Whenever you detach the filter from its frame that attaches to the aquarium, all the debris pours out from the bottom of the filter right into the tank. There should be a way to close all the suction holes during maintenance so the filth stays inside the filter. -After about 2 months of use, anytime I turn the filter off and on, the impeller does not start spinning. I have to detach the motor and spin the impeller with my finger in order to get it going. And yes, I have cleaned the impeller itself. The impeller cavity is also clean. -It's a pain in the rear to put the filter housing back into its frame. The housing does not want to lock into the frame. I do make sure the power cord is flat in its "cord trap", but this thing will fight you for a few minutes until it finally locks in. Good idea but not well executed. UPDATE: the more time i spend with this filter wanna be, the more I realize it's a complete failure. Look closely and you will see the tiniest of particles in your water floating by the filter like it has zero suction. Good luck with all that, Fluval! UPDATE # 2: Well the filter is now paper weight. The motor is almost dead. There is very little/non-existent water flow coming out no matter what I do. I have taken the media out, turned the flow knob in every which way and there is almost no output. The impeller is spinning but not that fast. And yes, the impeller has been cleaned along with the cavity it sit in.

I love the quietness this pump provides and my tank stays much cleaner than before. In my tank I have two 5inch red-eared slider turtles and they're very messy so finding this pump is a dream come true. It lost one star however because when I clean it sometimes when I plug it back in it won't turn on. I can only assume it's because the propeller becomes off balanced but if I take the time to pop off the bottom and clean it out every time I don't have that problem.

The following review was written by my 10-year-old son: I love this filter, the U2 filters my 10 gallon divided betta tank extremely well, I like how easy and simple the boxes are to put in and how easy it is to install. I like the venturi option and that's the one I use. NO need for an air pump, it has one. Awesome filter, but it came with a small part of the lid chipped and it takes up quite a bit of room. Overall, I recommend this filter, much better than most HOB filters. If you have the money definitely go for this one. Side notes: It does not have to be fully submerged if you are using the top nozzle with the venturi, instead leave everything submerged but leave the nozzle of the venture sticking out a bit so oxygen can mix with the air. You can also replace the cartridges with bio-foam inserts and you may need more biomax. This is an honest and unpaid review.

Be forewarned; this is a rant. I've had internal Fluval filters for years and years. The older models were simple, easy to use/clean and quiet!! I recommended them to anyone with planted, low-stocked tanks that hated to see equipment hanging all over. Now, they've been "improved" upon beyond usefulness. I still think they are one of the best internal filters on the market. Excellent water filtration, great options for filter media, nice to have 3 options of water flow (all top, all bottom or a vertical tube for middle flow). As a filter and quietness, it rates 5 stars -- ease of cleaning, 1 star, thus the 3 stars in the middle. But due to all of the little "quirks" you have to deal with in getting it cleaned, I'm looking around for a different brand that doesn't waste my time. Instead of quickly cleaning the filter and moving on, I have to block out big chunks of time simply due to poor engineering. Frustration-free they are not! The theory: To clean/change out the filter, pull filter from wall bracket, lift out. Clean. Return to bracket and push bracket closed, close the filter lid. Minimum fuss; no scrubbing of the hands/arms before putting them into the tank. Sounds easy. In reality: Because the filter is difficult to pull out from the wall bracket, I usually end up pulling the wall bracket out too (which means I've had to delve into the water to loosen the suction cups for the wall bracket -- gotta hand it to Fluval, their suction cups are sturdy and hold extremely well -- so it's a battle to release those cups). Because the power cord is now wound thru bracket slots on the back of the filter, I suspect the cord keeps the filter from easily sliding in and out of its bracket. OK, back to cleaning: In order to open the bottom propeller section for cleaning, you have to unwind that slimy wet cord from its bracket slots on the back of the filter. Once cleaned, you have to rewind the cord back into the slots - difficult to do as everything is a very, VERY tight fit. Yes, you do have to rewind the cord back into the slots -- the filter won't fit back into its bracket otherwise. Keep in mind that the bracket slots have created a permanent slight "S" curve to the cord, so when you re-wind it, you gotta get those curves put in the same position. If you are just changing/cleaning the filter and not dinking around with the propeller, you still have to pull it out from the wall bracket. Once you've opened the top cover of the filter, it tends to be difficult to snap it closed again. Remember, you paid for a system that you can easily change/clean the filter quickly without getting your whole arm wet. This is not that.

This is my favorite filter I’ve ever used. I saw someone else’s tank setup for an ACF and they had the water filled about half way of a 10g tank and it looked so great for the frog!! I wanted to replicate that but I would not with my old overhang filter. This filter is nice and quiet, you can control if you want airflow mixed in the outflow, and there are two outflow options you can choose from. You can also control how much outflow current you want. I was nervous because the filter looked more complex than my old one but it was really easy to figure out the controls. The instructions weren’t helpful in figuring out the controls, so before I put my frog in the tank I played around with it to figure out everything. The filter is the quietest one I’ve ever used and has great cleaning power. And it’s not expensive!!!

Don’t believe some of the reviews on here. It is not loud, it doesn’t break down, and is a great product. I use this on my Axolotl aquarium, mainly because it has the flow spreader which makes it a lot lower flow. I was worried when I got it because people said it was either noisy or broke down. I have had it running non-stop since I got it without an issue. This leads me to believe that people are doing something wrong or are inexperienced aquarium owners. I have multiple aquariums that use a broad range of fluval and have never had an issue with any equipment from them. I would recommend this filter 100% to anyone who wants something that does a great job of cleaning the aquarium and doesn’t want a HOB filter setup.

Ne ho provato davvero tanti e vi posso assicurare che sulla fluval vi potete definitivamente fermare. Per un acquario ci vuole quello👆. Il resto si, avvicina soltato e basta. Questo é l'aspetto positivo della fluval, un acquario per creare il giusto abitat per i pesci, serve quello. I filtri poi sono semplici da estrarre e pulire. È completo di tutto quello che awrve per far stare bene i pesci. L'aspetto negativo di fluval è che la pompa va sempre tenuta sotto controllo, si blocca prima o poi accade. In un anno soltanto può succedere e li avete bisogno anche del peggior articolo tenuto sempre da parte di scorta perché tanto accade sempre di domenica o pwr lw feste quando tutti sono chiusi. Fin quando funziona, bene, per i pesci é come farli vivere tutti i giorni in una Spa. ... Con quello che costa forse un po' più di accortezza la fluval poteva o potrebbe dedicarci a pro dei clienti che ancora ci credono. Ah dimenticavo?! Della fluval li ho provato tutti, in quanto ho avuto anche acquari da 300 litri. Questo è quello più piccolo da 60 litri Ma sì ancora li consiglio tutti i filtri loro.

We went from a noisy, sub-par, exterior filter that we had to change the filters once a week with & had to strip the tank & clean it, every 2 weeks. For 6 months we were doing this. So annoying & such a waste of time & money! A friend recommended Fluval & I was hesitant, but figured I've already wasted enough money with the other piece of junk, why not? Purchased in January & haven't looked back!!! What an amazing product!! Today (March 15, 2015) was the first major strip down tank clean we have done, since it's installation! Our fish & plants are thriving, it's quiet & I have yet to replace a filter! The filters rinsed clean with ease, each time I've done it. I have ordered more, for next cleaning though. This machine is silent & I love it!!

Vraiment top top rien a dire

I had a cloudy aquarium with a filter priced 400 rs. It had to run for a week to make the water clear and the water flow was strong which made the fish hard to swim on their own. But this filter does magic. With in some hours after installation, the water became crystal clear. The flow is very smooth too.

Lo queria para ponerlo en un tortuguero hecho por mi, para una tortuga Mapa. Con el anterior que tenia no duraba ni una semana y media y el agua ya estaba sucia. Con los tres departamentos que lleva te da mucho juego para poner SIPORAX MINI O CANUTILLOS O CARBON ACTIVO, es increible lo limpia que esta el agua y lleva ya casi un mes, el agua cristalina y la fuerza del motor perfecta. Ya no quiero otro filtro estoy encantado y mi Mari Juani a crecido sin tenerla que sacar para darla de comer fuera, sin riesgo a corrientes de aire ni que se ponga mala. Lo recomiendo es una maravilla lo bien que esta llendo desde que lo puse y como es grandecito la tortuga no puede moverlo que el anterior lo movia y lo paraba muchas veces, este lleva dentro de la tapa para hacer el chorro mas fuerte. Esta muy bien pensado todo para un acuario o tortuguero ¡¡ Lo tengo en unos 50 l y super contento GRACIAS FLUVAL .