10 Pack Filter Cartridge Compatible with Whisper Bio-Bag Filters 10i/IQ10/PF10, Medium Replacement Filter Cartridges for Aquariums Compatible with ReptoFilte 20 gallons (90 GPH)

It does the best at filtering the water!A great product. Will be using

This 10 pack is a good value alternative to the Tetra Bio-bag. My 10g aquarium uses the medium size and these fit well. The product (both the original and this copy) are quite simple: a fibrous pouch 1/3 filled with activated charcoal is fitted over a plastic frame with a handle on the top. a plastic clip keeps flaps on the handle clamped over the bag opening, keeping the activated charcoal contents inside. The internal plastic frame ensures that the filter assembly fits snug in the aquarium filter. Easy.I compared the contents of the filter with what is in the Tetra product. This one actually contains more activated material, though some of it is some sort of adsorbent balls, which look similar to other brand bio-filtration media, which means large surface area media to support growth of "good" nitrifying bacteria that develop in the aquarium as it cycles. This is a good idea, though these bacteria will also grow on the white pouch surface as well. See photo.Despite what the manufacturer may recommend as far as frequency of replacing these filters, many fish keepers view these filter media products as an important surface for essential bacterial growth and will keep the same filter in place for as long as possible (servicing only when it becomes completely clogged). To preserve bacteria, consider a vigorous rinse in used tank water when you do a water change and replace in the filter box. This way the bacteria on the filter media can keep processing ammonia waste without waiting for bacterial cycling.Hope this helps

I tried these on one of my well established fish tanks that houses mollies and snails. There was no excess debris and the tank is balanced.While this cartridge fits my filter, the inner and outer material is too dense to effectively filter for more than a few days before needing to be rinsed and/or replaced. It gets clogged with debris too quickly, causing the water to flow over the top of it. It also creates a backflow over the intake tube, which negates the purpose of the filter and was causing the water to turn cloudy. I put a regular Tetra Bio-Bag back in the filter and the water cleared up overnight.Normally, I need to change the cartridges about once a month; there's no way these cartridges would last that long.

First I want to mention... I've had my tetra whisper filter system forever, and although I've recently upgraded to a 55 gallon and added both a canister filter and a uv light filter, I still keep this system running, because #1 it's simple and efficient. It's easy to handle. Simply replace the filter bag! Turtles produce a lot of waste, and this thing has never once given out on me.To the point of this review... these filter bags are no different than the bags that come with the system. In fact I think they actually hold a bit more and the fabric is a bit thicker. I would actually prefer these bags over the ones I've had previously.Very fond of these filters, and at this rate I'll be back.

I bought these because the Tetra Biobag ones I normally buy (size M) were and are still unavailable. The material is more dense (not as coarse) and the charcoal did not appear to need rinsing (although I did still rinse them). I saw one review that indicated the filters did not work for very long due to the higher density (water got cloudy after only a week, when filter changes are generally only necessary once per month). I’m on day 3…time will tell. Personally, I’m not opposed to rinsing the filters every week or so, if necessary. But if this does become necessary because my water gets cloudy, I’ll probably be switching back to the Tetra ones as soon as they (hopefully) become available again. So far though, my tank is clear and my fish (and me) are happy.

Worth getting. Fit and you can still customize what goes in since these are not sealed completely. This I like.

These are a great replacement for the Tetra filters, they look just like them tbh.Water is clear and clean like it should be and my turtle is happy.

I change the filter in my 10-gallon fish tank once a month and always use the same brand (Tetra). This review is being done on Pyritier replacement filters for Tetra.As you can see in the attached photos, there's a noticeable difference in the amount of charcoal that's used in each. This brand uses considerably less. In addition, this brand has a really thick cover over the charcoal area, which concerns me as I want to think the water is filtering in and out with ease. Their website indicates that better thickness = better filtration, but I'm not convinced. Time will tell after I've used one for 30 days. If these prove to be better than Tetra, I'll update this review.The cost factor must be addressed. If I'm using a replacement instead of my usual brand, I'd expect it to cost less (like replacement ink for my printer). This however, is just the opposite. A Tetra 3-pack of filters sells for $6.68, or $2.22 per filter. Pryitier sells a 6-pack for $16.99, or $2.83 per filter. These replacements cost about $.60 more per filter than Tetra filters.The bottom line is that I'm not too impressed with these replacements. I feel like I'm paying more but getting less.