Which tank or filter do I have?

Fluval Flex 9 & 15: the original or the Flex 2.0?

The two look alike, but most of their parts do not swap.

• The lid. The Flex 2.0 lid has a feeding port with a small door, hinges at the back and risers. The original Flex has a large open cutout for feeding.
• The intake slots on the back wall. On the Flex 2.0 they are smaller and spread over a larger area.
• The return. The Flex 2.0 comes with a spray bar. The original comes with twin output nozzles.
• The color. The Flex 2.0 is sold in black only. A white Flex is an original. A black Flex can be either.

The Flex 32.5 is a different, larger tank with no 2.0 version. Parts for the Flex 32.5

Fluval Spec V 5 Gallon, Spec III 2.6, Spec 16 — or the Fluval Betta 2.6?

The quickest check is a tape measure.

• Spec V 5 Gallon: long and very narrow. Fluval now also uses "V" for the 16 gallon, so always check the gallons.
• Spec III 2.6 and Betta 2.6: the same water volume, but different tanks. The Betta 2.6 is taller than it is long. No nozzle fits the Fluval Betta tanks.
• Spec 16: much larger. Its parts are on our Evo 13.5 & Spec 16 page.

Legacy AquaClear or Fluval AC?

Fluval redesigned the AquaClear filters as the Fluval AC line. The lids of the two never fit each other.

• The name is on the box and on the lid. A Fluval AC filter has "AC" in its model name: AC20, AC30, AC50, AC70 or AC110. A Legacy filter says "AquaClear 20", "AquaClear 30" and so on.
• The shape. The Legacy AquaClear is much flatter. The Fluval AC has rounded sides and a curvier shape overall.
• The back. The Fluval AC has a raised back and a stepped edge where it hangs on the tank.
• Our shrimp guard strainers fit both, so for a strainer you only need the size: 20, 30 and 50, or 70 and 110.

Fluval canister filters

Our intake strainer fits the Fluval 105, 106, 107, 205, 206, 207, 305, 306, 307, 405, 406 and 407. It does not fit the FX series.