We have this on a small tank with 2 goldfish-- it works well to keep the tank clean.

Pros: works well, economical

Cons: none

This is a very economical filter, and the replacement cartridges are also affordable. I actually bought this filter to replace the in-tank filter that came with my 2.5 gallon tank. This filter is suppose to be for 5-10 gallon tanks, and I have no doubt it would be just as efficient. You can control the flow valve, so I have the flow set very low, so there is a very slight current, but my fish actually loves to dart around on the slight currents. I only run this filter for about one hour each day, and the water has remained crystal clear. It is very quiet while its running.

Pros: Great Filter, Quiet, Efficient

Cons: None Known

This filter works well and is inexpensive, but the motor quit on mine because we wanted the water in the tank to be filled to the top to look better. Very quiet and easy to clean.

Pros: very quiet, cheap filters, little cleaning needed

Cons: can't fill tank full

This is a very nice filter system for a fish tank.
I highly recommend this product.

Pros: don't take up much room

Cons: price could go down a bit