Fluval U3 Underwater Filter Probes & Accessories and test top off operation

and test top off operation before relying on unattended operation

Heavy wall PVC bulkhead fitting for durable installation

Does not contain nitrates

Recommended for aquariums up to 30 gallons according to common Aqueon sizing guidance

Use supporting KH and mineral balance products where required by the dosing method

Fluval U3 Underwater Filter Probes & Accessories and test top off operationFluval 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.