I have a Penguin 330 filter in my turtle aquarium. I has two cartridges and works very well. I rarely have problems with cloudy water. I change these cartridges about every two to three weeks, and they are very easy to change. I just take the old ones and throw them away. Then I can put the new cartidges in and that's it! I highly recommend this filter.

Pros: Last a long time

Cons: none

These inserts survive and survive and survive. You can rinse these badboys out many, many, many times before the poly material starts to break down. The carbon will of course, be exhausted after the first month, but it's cheaper to rinse these and add carbon behind them in a used nylon or filter bag and these inserts rock!

Pros: high quality insert

Cons: pricier than most other brands

I have a few Marineland filters,so I purchase a couple different sizes of filter cartridges.
Can be pricey,if you don't shop around,but they do work well for what they are.
Rinsing them out occasionally will lengthen their life span.

Pros: easy to find comes in different sizes

Cons: none

This filter works well - maintenance is required to achieve optimal results and prevent clogging.

Limited carbon in each filter.

Pros: Easy to use/maintain

Cons: could have more carbon per filter