The 9 Best C3 Water Filter

Unfortunately they clog up fast; although they may be efficient at cleaning; In my opinion these dual density pads don’t work with this filter. Within a week of replacing them the maintenance indicator pops up, and they have to be replaced again – when that happens the flow is reduced noticeably, since water chooses the path of least resistance it then goes up to the portion where the bio-screen/trickle portion of the filter is which feed by unfiltered water to begin with also clogs up pretty quickly, once these pads clog up it just speeds up the process of that portion of the filter.

As an FYI – once the pad is clogged you can remove the fine filter portion of ( it comes off easily), and reuse the coarser side after rinsing it in aquarium water and continue to use it; of course trading off fine water polishing for longevity.

Both the box and the description stated that it was a 3-pack, but BOTH boxes only contained 2 pads.There was plenty of room for the third.I find it very odd that both would be short one pad.This seems out of the realm of realistic possibility as far as packaging errors go, but I guess it is possible.

Amazon sent me another box, no hassle.This is the first time I’ve had a problem with an Amazon product and I am frankly amazed by their customer service.I did not have to send six emails and get worthless auto responses or call and play prompt lottery, explain my story nine times then get hung up on, etc.A rep called me and just took care of it within 3 minutes.This is unheard of these days.I’m very happy with my experience, however I only gave 4 stars due to the quantity issue.

Biggest issue: NOISE. The motor/impeller rattle like crazy, and it seems like a rather common occurence. All the "silent" reviews are from 2013, but more recent reviews agree with me. The magnetic drive shaft is not anchored on both ends - which means the non drive end is free to wobble and cause these rather obnoxious noises. It seems they changed something - and for the worse.

Second issue: that lovely "second top bio layer" works great for the first few days. But it's fed by a slipestream of the intake, PRE-filter, so the top of the cartridge just becomes clogged with tank solids.

UPDATE:Honestly after about a year or so these pumps can get noisy too.If you take out the impeller and clean it up and apply some Vaseline to the shaft, they will quiet down.I still prefer these filter pumps over anything else I've used.They are super easy to clean, reliable, and still pretty quiet even after constant use for a couple of years.

New Update:Granted I have had these pumps for a couple of years, but these pumps get super noisy and replacing the impeller doesn't improve it much or for very long.It's sux because besides the noise they are excellent.I am thinking of going back to the Penguin??I can't take the noise.They are quiet for a while, but eventually they are way too loud.I have two small Penguin 200's on my 40 gallon and they are nearly silent even after 4 years.

The Fluval series can be considered an upgrade to the workhorse Aquaclear series. I purchased the Fluval 20 as a replacement for my old filter. Setting it up was easy and straight forward, however after firing it up, water seemed to be leaking from it. Luckily I stayed around to see how it was operating, or many gallons of water would have ended up on the floor. After closer inspection, I found a substantial crack on the side of the filter, which was the culprit. I immediately sent in for a replacement by Amazon, and to its credit, the new unit arrived in a day. Another testimonial to the excellent customer service provided by Amazon.

The second installation went as easy as the first, but with more caution on my part this time. The new unit had no cracks or defects and has been running efficiently for several days now. The water had a haze, due to very small particulates that couldn't be filtered with the old Aquaclear 20, but after 3 days, the water is crystal clear.

I like the way this filter is compartmentalized for each filter medium, which means I can just pull out the carbon section, filter section, bio-stars, or bio-screen without disturbing the other three. The Aquaclear 20 had to have all three filter sections pulled out at once to exchange one of the media, and this left a horrible backup of debris being pumped back into the tank. Not a good thing and very unsightly.

There seems to be conflicting reports as whether these filters are quiet or noisy. I happen to be in the camp that says it is quiet. When starting up the filter, whether for the first time or when stopping it for feeding or maintenance, the noisiness does happen, but this seems to be the result of air being stuck in the filter. The impeller churns the air trapped in the system and this produces the noise. All that needs to be done is to make sure that the filter is completely filled with water (you can trickle some into the top of the filter as it's starting up) and this allows the air to be purged. You might have to quickly plug and unplug the filter several times to expel the trapped air. I also added a dab of Vaseline, as suggested by others. on the impeller shaft to help keep things lubricated.

Maintenance for this filter is a breeze, and the fact that you can rinse out the polyfoam filter (not in tap water, but treated water that has the chlorine neutralized so as not to kill off the beneficial bacterial) will save on costs. As a side note, my old Aquaclear 20 motor seems to be a direct twin of the Fluval 20 one, so I'll keep the old motor/impeller assembly as a back up for the Fluval.

The Fluval C2 is working exceptionally well, and the fish, (and the fish hobbyist, me) are having a great time. One star is deleted from this otherwise high rating due to an apparent lack of quality control or substandard packaging of the filter, as the first one I received was defective with a 3-inch crack down the side. Interestingly enough, another review described the same exact crack location and leak as I had on my filter. I wonder if the defective one was somehow recycled and resold? I guess I'll never know.

If you're looking for a very good filter that will keep your aquarium water looking crystal clear, assuming that all your other water parameters are decent such as pH, nitrate levels, ammonia levels, and nitrite levels, the Fluval C2 should work well for you.