• 140 L/min air output — rated 8,400 L/h, double the BIS650's output, for ponds up to approximately 16,800 litres.
• 33-outlet manifold — enough outlets to run a large pond's worth of airstones and diffusers, or aerate several holding tanks, from one pump.
• Dual-chamber, oil-free diaphragm design — no oil in the airline, and two chambers smooth the pulse compared with a single-diaphragm pump.
• Dual air filtration — filters intake air before the diaphragms, which matters more at this duty cycle than it does on a smaller pump.
• Manifold, clamps and adapter included — the 33-outlet manifold, stainless steel/spring hose clamps and manifold adapter are in the box.

As with the smaller BIS650, Bioscape doesn't publish a quantitative air-output-vs-depth chart, unit weight, dB noise figure or a stated AU warranty term for this pump.

The BIS650 and BIS651 share the same build and the same 1.8m cord — the difference is scale. If your outlet count is climbing past what a 14-outlet manifold can comfortably feed, or your pond is pushing past roughly 8,000 litres, the BIS651's extra 50W and 19 extra outlets give you the headroom without running a second pump.

As with any air pump, output falls as back-pressure rises — depth, airline length and the number of outlets actually in use all add resistance the diaphragms have to push against. Bioscape's guidance for this range is to use wide-bore airline, keep stones clean, and keep diffusers at shallow-to-medium depths of around 4–5 metres or less; deeper placement will noticeably reduce delivered air below the 8,400 L/h rated figure. No quantitative output-by-depth table is published for this model, so treat 8,400 L/h as the pump's rated free-air output rather than a guaranteed per-outlet delivery once all 33 outlets are in use — spreading a heavy load across fewer, larger stones will generally outperform running every outlet at once.

• Bioscape Heavy Duty Pond Air Pump (BIS651)
• 33-outlet manifold
• Stainless steel / spring hose clamps
• Manifold adapter

Airline tubing, air stones/diffusers and check valves are sold separately.

• Suitable for: larger outdoor ponds up to roughly 16,800 litres, multi-tank aquaculture or holding setups, and any system where a 14-outlet pump would be maxed out.
• Not suitable for: submersion — it's a surface-mounted unit — or small ponds and single-airstone setups, where the smaller BIS650 does the job for less outlay and less running cost.

Rated 220–240V / 50Hz with an AU plug. Site it above the waterline in a dry, ventilated position — this is a surface air pump, not a submersible one — and keep it protected from flooding in heavy rain, particularly given the larger 100W draw.

Covered against manufacturing defects on arrival, in addition to your rights under Australian Consumer Law. Bioscape's AU site doesn't publish a specific warranty term for this model — contact us to confirm before ordering. Standard parcel delivery applies.

What's the difference between this and the BIS650?

Output and outlet count. The BIS651 delivers 8,400 L/h through 33 outlets at 100W; the BIS650 delivers 4,200 L/h through 14 outlets at 50W. Both share the same dual-chamber, oil-free design.

Can I run fewer than 33 airstones off it?

Yes — you don't need to use every outlet. Running a partial load generally gives stronger flow per stone than loading all 33 at once.

Is it submersible?

No. Mount it above the waterline in a dry, ventilated spot and run airline down to your diffusers.

What size pond is this rated for?

Approximately 16,800 litres, per Bioscape's specification.

Does it come with air stones or airline?

No — the 33-outlet manifold, hose clamps and manifold adapter are included; airline tubing and diffusers are sold separately.