Compatibility:

Specifications

Fluval item #A20216, UPC 015561302166. The AquaStop valve for the FX series — the click-fit valve block that lets you shut the water off and lift the hoses away without draining the tank into the cabinet.

Fluval publish no dimensions for it. The item number is the identification that matters.

Compatibility

FX2, FX4, FX5 and FX6. That is Fluval’s own compatibility statement for A20216 — all four FX canisters, including the FX5, which our product title leaves out.

It does not fit the 07 or 06 Series canisters; those use their own AquaStop, supplied with the filter.

Setup & Use

The valve is the first thing you touch in any service. Fluval’s sequence for draining an FX begins by turning the IN and OUT valves in order to the closed, horizontal position, and only then unplugging the pump and disconnecting. The lever positions matter: vertical is open, horizontal is closed.

On the 07 Series, Fluval replace the AquaStop O-ring gaskets yearly. They are not on the FX chart as a separate line, but they are the same kind of part doing the same job, and a valve that has started to weep is telling you the gasket has gone.

Silicone lubricant only. Fluval are explicit about this in both the 07 Series and FX manuals: seals and O-rings are lubricated with a silicone-based lubricant only, and they name their own Fluval Silicone Lubricant (item #A325). Petroleum jelly and vegetable- or animal-based products are not to be used, and Fluval say that using anything else voids the guarantee.

Close the valves, unplug, then drain. Before any part of a canister filter comes off, Fluval’s sequence is: turn the IN and OUT valves to the closed (horizontal) position, unplug the pump, then disconnect. The canister sits below the tank and is full of water — opening it in the wrong order empties it onto the floor, and on an FX4 or FX6 that is fourteen to twenty litres.

Safety & Precautions

Close the valves, unplug, then drain. Before any part of a canister filter comes off, Fluval’s sequence is: turn the IN and OUT valves to the closed (horizontal) position, unplug the pump, then disconnect. The canister sits below the tank and is full of water — opening it in the wrong order empties it onto the floor, and on an FX4 or FX6 that is fourteen to twenty litres.

Unplug everything in the tank before your hands go in the water. That is Fluval’s own instruction and it covers every appliance in the aquarium, not just this one. Grasp the plug and pull it; never yank the cord.

A spare is only as safe as the unit it goes into. Fluval’s standing instructions still apply to the filter itself: the power cord cannot be replaced or cut, a unit that has been dropped or shows abnormal leakage should not be put back into service, and repairs go to an authorised service facility rather than a kitchen table.

What’s in the Box

One AquaStop valve. Fluval do not itemise the pack further — there is no hosing and no lubricant in it. Ribbed hosing is a separate part (A20236), as is Fluval Silicone Lubricant (A325).

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number, or email us if you would rather, and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.