I have a Whisper Hang on tank Filter 20. Whisper Bio-bag filters work great.
Then I discovered the Bio3 alternative made by somone else to fit the Whisper (also comes in other manufactures' sizes). I've seen it under different names such as Dr. Foster Smith Bio3. In the catalog it looked so much better & cheap. It has a bio sponge, a more sturdy looking frame & better distribution of carbon. Unfortunately I bought a year supply. They are much too thin, they waste so much space in my filter & they clog fast (my fish are messy slobs). I bought some bio max media to throw in the filter & that's been enough to get three weeks out of a Bio3.
Stick with the Whisper Bio-bag.
Then I discovered the Bio3 alternative made by somone else to fit the Whisper (also comes in other manufactures' sizes). I've seen it under different names such as Dr. Foster Smith Bio3. In the catalog it looked so much better & cheap. It has a bio sponge, a more sturdy looking frame & better distribution of carbon. Unfortunately I bought a year supply. They are much too thin, they waste so much space in my filter & they clog fast (my fish are messy slobs). I bought some bio max media to throw in the filter & that's been enough to get three weeks out of a Bio3.
Stick with the Whisper Bio-bag.
