Blue Pet BLH-301 Aquarium Hang on Filter 3 watts

The Blue Pet BLH-301 is a 3W hang-on-back (HOB) aquarium filter delivering up to 180 L/H, a compact, quiet filter that hangs on the rim to keep nano and small tanks clean while saving space inside the tank. It traps debris, food residue and particles for clear water, creates a gentle waterfall that oxygenates the surface, and is simple to install and maintain — an easy entry-level HOB for small setups.

Why choose the Blue Pet BLH-301?

• Compact 3W HOB with 180 L/H flow for nano and small tanks.
• Hangs on the rim — no space used inside the tank.
• Waterfall return that oxygenates the water surface.
• Mechanical + biological filtration via the filter cartridge.
• Quiet and easy to maintain.

Specifications

Which tanks is it best for?

With 180 L/H, the BLH-301 suits nano and small tanks up to roughly 40L. For slightly larger tanks see the BLH-401 (250 L/H) or BLH-403 (500 L/H). Learn the format in 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 cartridge 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-301 for?

Nano and small tanks up to roughly 40L, based on its 180 L/H flow.

Does it oxygenate the water?

Yes. The waterfall return agitates the surface and improves oxygen exchange.

Is it quiet?

Yes. It is designed for quiet operation.

How do I maintain it?

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

Should it run all the time?

Yes. Keep it running 24/7 so the beneficial bacteria survive.

New to filtration? Read our complete aquarium filter guide and types of aquarium filters.