Review on 🐠 Fluval U4 Poly-Carb Cartridge - Replacement Underwater Aquarium Filter Media (2-Pack) - A492 by Jennifer Hirsch

I am using a U4 filter with a Fluval aquarium filter in a 55g pack for aquatic turtles. Together they keep the tank in order and are cheaper than the FX I want. However, this is a short-term fix and the filters are on opposite ends of the tank to push out the dirty water. So as long as it works I wouldn't recommend it to others who can afford the Aqua Turtle FX series. This is the best for fish and I have had no trouble getting my feeder fish into this filter. * Change only one side at a time (there are 2) to keep good biological bacteria.