Fluval U3 Underwater Filter Probes & Accessories Does not contain nitrates

Does not contain nitrates

and test top off operation before relying on unattended operation

filtration media

Instead of running every compatible 24V device from its own external adapter

and wireless app control

Fluval U3 Underwater Filter Probes & Accessories Does not contain nitratesFluval U3 Underwater Filter The Fluval U3 Underwater Filter is an internal aquarium filter for aquariums up to 40 US gallons 150 L, offering 3 stage filtration, adjustable flow direction, and in tank water movement for freshwater, saltwater, or compatible reptile setups. Internal Filtration for Medium Aquariums The U3 is designed for aquariums that need more internal filtration capacity than the U2 while still keeping setup simple and self contained.