• One assembly, two filters — fits both the BIS499 (350 L/h) and BIS500 (550 L/h) Tropic hang-on filters. Check the model number printed on the motor head rather than guessing by flow rate.
• Restores rated flow — mineral build-up and wear on the impeller and shaft are the most common reason a hang-on filter loses flow over time. A fresh impeller brings the pump back to its rated output.
• Fits without dismantling the filter body — the assembly lifts out of the motor housing on both models; the media baskets and filter body are not disturbed.

Bioscape's Tropic hang-on range runs from BIS499 up to BIS502, and the impeller assembly is not shared across the whole range. This listing covers the two smallest models, BIS499 and BIS500. The larger BIS501 and BIS502 use their own impeller assemblies — see the BIS501 impeller assembly and BIS502 impeller assembly if your filter is one of those models.

Suitable for a Bioscape BIS499 or BIS500 Tropic hang-on power filter that has lost flow, become noisy, or stopped running. Not suitable for Bioscape's Tropic canister filter range, or for the larger BIS501 and BIS502 hang-on filters, which take a different impeller.

Covered against manufacturing defects under Bioscape's spare parts warranty, in addition to your rights under Australian Consumer Law. Ships by standard parcel post.

How do I know if my filter is a BIS499 or a BIS500?

The model number is printed on the motor head of the filter. Both models take this same impeller assembly, so you don't need to identify which one you have before ordering.

Do I need tools to fit it?

No. The impeller lifts out of the motor housing by hand on both models — no screws or clips hold it in place.

What causes a Bioscape hang-on filter to lose flow?

Mineral and debris build-up around the impeller and magnet increases friction and wears the shaft and blades over time. Replacing the impeller assembly is the standard fix, rather than replacing the whole filter.