Perfect filter for low water level setups!
928733
There are 3 varieties of the Duetto filters. They are:
Mini up to 10 gallon 2-40 GPH 2-1/2" x 1-3/8" x 5-3/4"
DJ-50 10 gallon 13-66 GPH 3-1/4" x 1-1/2" x 5-1/2"
DJ-100 20 gallon 27-92 GPH 3-1/4" x 1-1/2" x 7-1/4"

These filters have all the necessities: a prefilter/mechanical, a biological filter, a carbon/chemical filter and an air intake that allows the air to mix with the water that comes out of the spout. It is also an extremely quiet filter as long as you keep the pour spout below the water line (to prevent the sound of the water splashing). The only slight problem that I can find is that a tiny amount of air leaks around the seal between the filter media container and the top section, but this isn't a big deal since the water level will almost always be lower then this seal. It's also an efficient filter that produces less heat then most others.

You can use the filter as a pump by removing the pour spout and plugging in a hose that has an inner diameter of 1/2".
2305810
This was a perfect fit for our Fridgidaire side by side, model # PLHSZ69ZDB0. Found a video on Youtube to help me figure out how to install the filter.  It was super quick and easy!  Be sure to flush your water for a bit after installing the new filter before drinking.  I have very acute senses, and can definitely taste the difference in the water with the new filter!  Very glad to find an acceptable filter for less than the absurd retail cost of the PureSource 2 filters.  Yikes!
4081837
I have a 1500 gallon pond and the pump/filter needed to be replaced. The pond clarity was very bad and I did some looking around for solutions. Very happy I changed out the filter with this Flexzion. It was easy to setup and install. Was worried about the UV light, but waited till nightime and then you could see it working through the sightglass. This filter cleared my murky pond in less than a week. I can finally see my fish and turtles again!
1632501
Great price for a nice little filter. Fits well in my 5.5 gal betta tank and gives him a low enough current that he can swim around and not be pushed C: Love that there's 2 sponges so that you can rotate cleaning them every other week so your cycle doesn't get messed up.

If you buy one of these and are new to sponge filters, make sure you also buy:

-Air pump (I recommend whisper brand, super quiet and works great)
-Check valve (to keep water from flowing back into the air pump)
-Airline tubing (may be cheaper to get in Walmart depending on shipping and add-on prices)

The instructions to set this up were not in English, but it's super-simple. Connect the tubing to the air pump, connect the other end of the tubing to the small tube next to the bigger tube on the sponge filter, stick the filter into the water and use the suction cups to make it stay where you want it, cut the airline tubing about halfway to the pump and put the check valve there. Plug in the air pump and you're set if you see bubbles coming out of the big tube C:

I've got 4 of these, one of which has been running for over a year, and the sponges are still in good condition.
871844
Works better than expected and I can see improvement in water clarity in less than a week.  My pond is about 2,000 gallons and exposed to direct south Texas sun most of the day. The filter is fast and easy to install and comes with everything need except hose clamps. It took me less than a half hour to install.  Good filter for cleaning and removing algae and other small particles. Recommended to my fellow pond owners.
154185
Great filters at a fraction of the cost. Definitely make sure you run water through till clear ( almost a gallon) but then excellent tasting water!
2282381
Awesome! These filters are really great for my tank. It keeps the water clean and they last a long time with only fish in the tank.
2187271
It took me about 6 months to actually get around to installing this in our pond, mostly because I was redoing the waterfall but I'm also quite lazy.

Previously I had tried using a 200 gallon gravity filter, media filtration, and a skimmer/pump combo. In all cases there was little improvement on algae blossoms, mosquito larvae, and water quality. After talking to a local shop, I sought out this specific filter because they had a lot of success with a showcase koi pond located behind the store.

After reading the relatively detailed instructions and following the advice of pond enthusiasts, installation took about 4 hours due to the rocky soil (it doesn't have to be in the soil but can sit flush). Since filtration efforts had been miserable failures prior to this, my hopes were high but my expectations sat far lower, so I plugged it in and went about my business.

Two weeks to the day, my pond is clear enough to make out fine details along the bottom; including areas where green frogs have burrowed into the muck. Not only is the pond clear enough to make out fine details, I finally discovered where a slow leak was coming from (liner is sinking). As a final reward, of sorts anyway, there was also a revelation in finding two long forgotten lawn ornaments, a bunch of toys tossed in long ago by my daughter or her friends, and the skeletal remains of a cat.

I will have to wait until spring and summer to see how well the UV works on controlling algae at peak levels of sunshine and mosquito larvae but with the rapid development of clarity I am feeling confident that we'll be able to maintain good water quality. Highly recommend this filter!
2641515
Made the water in my aquarium very clear. The setup was very easy and works better than my previous filter. Keeps the water very clean. It is also very quiet based on my experience for the past 3 days.
441208
These filters are great! Houston tap water is disgusting with high levels of chlorine, chloramine and full of all the other byproduct compounds. I installed a 5 stage reverse osmosis system that helped, but the water still tasted too bad to drink. I replaced the first cheap granulated carbon stage  with one of these Purenex block filters and WOW, I have perfect tasting water now. Yes, there was carbon dust in the bottom of each filter. Just flush them first. I bought some extra 1/4" tubing and diverted the first few gallons into a bucket before putting it inline with the rest of the RO system.
3945609
This filter is great! I currently use it for a 40 gallon tank with two RES turtles, and it has keep the tank nice and clear since day 1.

WARNING: THIS FILTER DOES NOT COME WITH BIO MEDIA!

Bio media is important to have, as that is what removes the harmful chemicals from your tank from your pet waste.

Aside from that, the filter is quiet (a low pitch drone is all you hear), it works great, and depending on how dirty your tank gets, doesn't require constant cleaning. The base is rubber and keeps it nice and stiff. Hoses are a little stiff, but not too hard to work with. I recommend lubing up the hoses when pressing them onto the plastic hardware, either with water or saliva, as it makes it much easier to work with.

Cons: The very long intake tube, which would work great for taller tanks, but for shorter ones, you will need to use several of the included suction cups to secure it at the appropriate height, or, risk modifying the length yourself to better suite your tank.

The outake spray bar (or large spout that is also included) also sits quite high, so if you are like me and have a turtle tank, it will most likely be spraying quite a lot of water, and thus making a lot of noise if the water level sits below the spray bar.

What you could do is buy some hose at your local fish store that will fit as an extension between the outake tube and spray bar. Then, you can lower the spray bar to your tank's setup.

I highly recommend this filter.
2760039
I'm using this filter in a 20 gallon tank. It was easy to set up, and it's easy to maintain and operate. I like the ease with which the extension snaps into the suction tube. Discharge flow "lays" on the water in a flat/wide pattern, and is a snap to control. Excellent price!!

This filter is a "Silent Runner"  -  Runs very quiet, and has been working great for quite some time.

Highly recommended.
5 Stars
.
4224572
Great filters!  Fits just right on our motorhome water system.
26904
When we received this filter, we were up and running with pure filtered water within five minutes. Very easy to set up, and we noticed a difference in taste right away.

Highly recommended!
1546126
Great HOB Filter, easy to set up though they did give me a very long netted bag for the bio max but i just wrapped it around a couple times. I had custom cut the plastic part of my class hood to fit this unit in perfectly, it would seem that putting it on the right side of the tank allows for better filtration because on the left side the waterfall current pushes it away from the intake so I moved it to the right side and it did the trick, allowing for the debris to make its way around the tank and into the intake. to get this unit started you just poor some water into the left side where the motor is located and this part is noisy probable due to the air and water mixing in the motor but once all the air has made its way out this unit becomes very quiet unless you leave space for the water to drip/fall down then you get the water fall noise but that is easily taken care of by just adding more water to your tank closer to the spout of the filter. But leaving the water lower does allow for the water to be aerate more. also after reading some of the reviews it is clear to just clean the sponge and possibly replace the carbon leaving the bio max untouched to not disturb the beneficial bacteria that grow on it cause tap water will kill it. I'll also try to find some time to take a picture of my set up once my tank has finished cycling due to me completely removing all my other filters and doing to much water change I'm stuck with my tank cycling :(. in all I have nothing bad to say about this product and even for being the lowest of the AquaClear line it is very powerful and you will notice that when you put the setting on max. I just turn it down when I'm feeding them or it's night time so i don't disturb the fish with the strong current though i don't think they mind to much cause they just move to the other side of the tank or play in the current. I am hoping that with this filter and a canister filter on the side to allow for top,mid & bottom filtration i will be able to successfully overstock my 10g tank. you don't even want to know how many fish i have in there haha. but it's been about 3 weeks and they are all still alive and doing well, only another 3-5 weeks to go until my cycle is over. SO for this product I definitely give it 5 stars. i hope this review has helped in your decision and if you have any questions just comment this review or how ever this works. i just never left reviews for the things i've bought before and now over the 100+ products i've bought i'm trying to go through each one and leave a review :)
1198457
This is a great undersink filter that isn't too intrusive on space, and provides great quality water. As an example, since using this filter (over a year now), I haven't had my coffee machine complain about de-scaling even once. Water tastes great, and replacing the filter takes less than two minutes.
2919094
Acceptable pre-filter in my multiple filter household water system.