Blue Pet BLH-403 Aquarium Hang on Filter 8 watts

The Blue Pet BLH-403 is an 8W hang-on-back (HOB) aquarium filter delivering up to 500 L/H, with a built-in surface skimmer that clears the oily film off the water as well as filtering debris — keeping small-to-medium tanks clean, clear and well-oxygenated. It hangs on the rim to save space, creates an oxygenating waterfall return, and uses a 2-layer filter system for fast, effective filtration. A strong, feature-rich HOB for everyday tanks.

Why choose the Blue Pet BLH-403?

• 500 L/H flow from an 8W motor for small-to-medium tanks.
• Built-in surface skimmer removes the oily film from the water surface.
• Waterfall return for strong surface oxygenation.
• 2-layer filtration — mechanical and biological.
• Hangs on the rim — no space used inside the tank.

Specifications

Which tanks is it best for?

With 500 L/H, the BLH-403 suits small-to-medium tanks up to roughly 120L, and the surface skimmer makes it especially good for tanks with an oily surface film. For smaller tanks see the BLH-401 (250 L/H); for a skimmer model with lower flow, the BLH-302 (300 L/H). See canister vs HOB vs sponge.

How to set it up

Hang the filter on the back rim, prime it if needed, and plug in. Keep it running 24/7, and rinse the filter layers in old tank water (never tap water) when flow slows. See how to install an aquarium filter.

Frequently asked questions

What size tank is the BLH-403 for?

Small-to-medium tanks up to roughly 120L, based on its 500 L/H flow.

What does the surface skimmer do?

It draws in the oily film that collects on the water surface, improving gas exchange and clarity.

Does it oxygenate the water?

Yes. The waterfall return plus skimmer give strong surface oxygenation.

How do I maintain it?

Rinse the filter layers in old tank water when flow drops, usually every 2–4 weeks.

Should it run all the time?

Yes, keep it running 24/7 to protect the beneficial bacteria.

New to filtration? Read our complete aquarium filter guide and how aquarium filters work.