This is a great choice for a small paludarium, say, 3 gallon capacity or less. It is easy to use, and inexpensive. Out of the box, I had a problem with debris in the tank being pulled into the pump intake basket, slowing down the water flow. This can be cleaned out by removing the two screws on the bottom of the filter housing, removing the basket, and rinsing everything clean.

Eventually, I got some coarse sheet foam and wrapped it around the intake slots, securing it in place with rubber bands. This helped the clogging problem immensely. BTW - this same filter is sold by Tetra as the Reptofilter at twice the price. The only difference is that the Reptofilter has a thin plastic cover over the top of the filter, ostensibly to prevent amphibs from crawling into it. I've never had a problem with that, and if I did, I'm sure I could come up with my own fix for considerably less than $9.00.

The filter is a biofoam bag which will encourage the growth of bacteria to eliminate ammonia and nitrates. The bag is filled with activated charcoal, so you get biological, charcoal and mechanical filtration.