• Twin outlets, 360 L/h total (180 L/h per outlet) — enough for two sponge filters, airstones or ornaments running together.
• Stepless adjustable flow control on each outlet — dial each line up or down independently without adding back pressure.
• Two check valves included — one per outlet, protecting against back-siphon.
• 4 W energy-efficient motor — low running cost for continuous, round-the-clock use.
• Freshwater and marine safe — suits community, planted and marine sump setups.

The 4000 shares its total output and tank-size rating with the Tropic 3000 — what it adds is control. If the two devices on your two lines need different flow rates (say, a deep airstone on one side and a shallow sponge filter on the other), the 4000's independent adjustment does that without pinching the line, which is the one thing that does add back pressure and shorten diaphragm life.

If both lines only ever need to run the same, fixed output, the Tropic 3000 does the same job without the extra dials.

Suitable for two airlines in a tank up to 300 L where each line needs its own flow rate — a mix of devices, uneven placement, or two tanks of different sizes off one pump. Not needed if both lines will always run identically — the fixed-output Tropic 3000 covers that case.

Draws 4 W. Run continuously, as aquarium air pumps typically are, that works out to roughly 35 kWh a year — around $10.50 a year assuming a 30c/kWh electricity tariff. Actual cost depends on your own electricity plan.

Mains-powered — position the pump above the aquarium's waterline where possible, and keep both check valves fitted if the pump sits at or below water level, to prevent back-siphon during a power outage.

Keep the housing dry and the intake vents dust-free. Use the flow control to reduce output rather than pinching or kinking the airline — pinching adds back pressure that shortens diaphragm life. A drop in output despite the control being open usually means the diaphragm needs replacing; the Bioscape BIS54A replacement diaphragm (2-pack) is sold separately for this model.

Covered under Bioscape's manufacturer warranty against defects, in addition to your rights under Australian Consumer Law. Standard parcel delivery.

• Airline tubing — enough to run both adjustable outlets to their airstones or filters.
• Airstones, sponge filters or air-driven ornaments — mix and match, since each line adjusts independently.
• Replacement diaphragm (BIS54A, 2-pack) — the standard service part for this model.

What does the flow control actually change?

It adjusts the air output on each outlet independently, without adding back pressure the way pinching the airline would — useful when the two devices on your two lines need different amounts of air.

Is the 4000 quieter than the 3000?

Bioscape markets both as quiet-running; no decibel figures are published for either model, so there's no measured difference to report.

How much does it cost to run?

At 4 W run continuously, expect roughly 35 kWh a year — about $10.50 annually at a 30c/kWh tariff.

Is it reef safe?

Yes, it's rated for freshwater and marine use, including marine sumps.