Finnex Carbon Filter Cartridge Pad, Nano Filter, Fits PF-7 and PF-5, 6 Pack

I use this little filter on a 2.5USG plant grow out aquarium -- growing out plants as well as Endlers Livebearer fry & snails. Set on minimum flow with modified media (not using the cartridges available for the filter).... Have the little thing doing every aspect of filtration with heavy concentration on biological....Here's my setup for crystal clear water:• Main filter box has a layer of crushed lava rocks -- about half pea size --• A coarse sponge layer (15ppi) on top, .3" thick• A finer sponge layer (30ppi) over that, .5" thick• 2 layers of 2 diff't types of chemical media wrapped in poly-fiber• Topped off with another bit of coarse sponge• The outflow has a bit of bonded (blue/white) media & a thin layer of coarse sponge• The intake box also has a 30ppi section of sponge at the back and smaller sections of 15ppi along the sides.• The bottom of the uplift/intake tube is encase in a coarse sponge (15ppi) sleeve which acts as a pre-filter to keep plant matter out of the filter (and available to snails), but also protects the young fish and snailsWith the above formula + live plants, the little aquarium doesn't even require regular water changes for parameters to stay perfect & the water clear.... Only time there is any water change is when fish or plants need to be pulled out for sale or to be moved into a diff't aquarium. The chemical media gets changed out every 5-6 months or when flow rate shows a need for the bio-media to be rinsed. The pre-filter does need to be cleaned up a bit more often, but that's only because the tank is used for growing out plant clippings from plants with fine leaves that get into the water column.As for noise level.... The filter is fairly quite; one of THE quietest I've used at this size .... There is a low, constant hum from the motor which is amplified by the glass aquarium, so I put a bit of noise deadening, thin foam between the motor housing and the glass.... The cover also doesn't lock into place, so it can rattle from the motor's vibration --- I remedied that with a couple of small, but heavy, decorative rocks in just the right spots.As far as suitability.... A lot of folks like to get these little filters for Bettas..... So, I will address that.... For a Betta, 52gph is suited for 5-7 USG aquariums. It's not as simple as just the gph, however.... This filter isn't suited for small spaces where the flow gets turned back around too quickly as that amplifies the flow rate too much for a Betta -- bowls and vases, for example.Some noted the minimum tank line being of concern for rimless tanks or waterfall creation..... I think ppl are misunderstanding what that minimum water line actually means.... It's the minimum water level for starting the filter, not for it's continuous operation..... Once the filter is started and running, the minimum water line is actually the first joint on the uplift tube, so water can be lowered once the filter has reached stability (not spitting out water bubbles). The uplift tube joint sits about 3 inches below the minimum water line on the filter box itself. That makes this little filter suitable for creating little water falls or keeping the water level down a bit for fish that like stronger currents. This filter is NOT suitable for high bioload fish of any kind.I'd have no reservations in recommending this little filter for light bio-load aquariums from 3-8 USG. For seasoned, knowledgeable aquarists/hobbyists, the filter is surprisingly customizable -- can even make for a highly effective 100% bio-filter.

This is a very small outside power filter. While I am not familiar with the brand, it has a solid build to it. Its no different than a mfg like Hagen. It is designed for small aquariums - it is listed (when running optimally) @ 52 gallons per hour. This filter is purely for mechanical filtration as it uses a sponge and small cartridge. There is no room for any filter media to enhance the growth of bacteria. We have it a aqueon 3 gallon aquarium with a few goldfish. It replaced a 25 gph submersible filter as we were having chronic problems with cloudy water. I don't care what the mfg says, I wouldn't use it above a 5.5 gallon aquarium or so. You really cannot beat it - especially at this price point.

I have several of theses filters and will buy more if needed. They have an adjustable flow rate which is great and are almost silent. I recently had one start leaking (about 18 months old, so that wasn’t great) and had to run to the store for a replacement. The one at the store was so loud I almost shut it off while I waited for this one to arrive. There is enough room to add your own filter media if you want to. I have four of them running currently, and as long as they don’t all start leaking relatively short period of time, I will keep buying them. Hoping the one that leaked was the exception to the rule. Great filter for the price.

I purchased this filter for my 5 gallon tank. The goal was to provide enough flow and filtration without creating too much surface agitation for a betta fish.The filter is small and looks nice. Looks are not really a thing most peoppw care about for hang-on-back filters, but I do appreciate that this one is sleek (for an HOB filter). It comes with a pre-filter that you can put on the intake, so you don't have to buy one separately.The media compartment is a bit small, but you can work with it. I recommend a simple modification: add a larger biofilter and/or add a bag of filter media. Discard the cartridge. Add some filter floss.The flow is adjustable via a simple knob. You can reduce the flow considerably per your needs. Even on the lowest flow, I am satisfied with the amount of water movement I observe in the tank.For me, the filter makes a squealing sound that increases in pitch, goes away and starta up again. Not sure why this is happening, but it could annoy some, depending on how close to it you are.Also, the filter doesn't reestablish flow after a power outage if the water line left in the filter is lower than the indicated minimum level, which is effectively anytime the power goes out. This has not been an issue for me, but will be eventually, and could be for you. I included a photo that shows the minimum water level for your reference.

I've been in fish keeping for over 20 years so I've had alot of filters in that time. This is definitely the best HOB filter that I've ever owned! I have it on my 10 gallon freshwater planted tank & it's working great! It was super easy to set up, primed itself when plugged in & also after a power outage, it has adjustable flow, keeps my tank clean, no leakage & I absolutely love the slim design! I plan on ordering the larger sizes of this filter for my other tanks. The filter cartridges are fairly priced too which is another plus. I highly recommend this filter!

What I really like about this filter is that it’s fairly hidden compared to other filters, as well as you can adjust the water flow and that is perfect for my bettas (I have two of these filters). As far as noise goes, it’s quiet but sometimes you can hear it buzz randomly. The pictures shown are about 2 months after I got the filter and as you can see there is growth, in the sense of natural growth it’s clean! And as you can see the water is still fairly clear so the performance of this filter is great for two months, but will be replacing filter pad soon. The stability is great as well, very nice fit and perfect for a 5 gallon!