Tetra Whisper Assembled Bio-Bag Filter Cartridges, Small, 4-Count

I got one of these cartridges when I bought the filter device, and I was very happy with it. It kept my 1.5 L gallon fish tank clean. So, I decided to buy it again, but these cartridges leave a white film on top of the fish tank. I contacted Tetra customer service, and of course, they blamed the water. I changed the water and the water source several times, but I still have this white film. Also, I have never had this problem with a different cartridge brand.

These little bio-bag replacement filters pack a big punch. The mechanical filter fiber works very well and the carbon is sealed into compartments to keep it from falling to the bottom and decreasing efficiency. Very impressive. for their size.

These little filters are perfect for my 2.5 Gallon tank.

Does the job, no problems. Fits my globe aquarium with waterfall that I also bought on amazon

I love them. I have not tried any other and my tank is small. But they keep the water crystal clear. I do a partial water change once a week and replace them about once a month.

Over the first night after changing the filter, the water became cloudy and my son’s beta fish died. I don’t recommend this product.

I love these tiny filter cartridges. I have a desktop aquarium at work, and the Whisper filter is more than adequate for my needs, plus the cartridges are simple to replace.

Excellent product & customer service!