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Pump curves, not box GPH

The calculator solves operating flow where pump head meets plumbing, filter and chiller resistance.

6 supported pump curves
Marginal results are downgraded when the curve is approximate.
Curve B

Active Aqua AAPW400

Curve points are approximate digitization anchored to manufacturer rated flow/pressure.

Zero-head flow370 GPH
Max head7.4 ft
Power24 W
Connections1/2 in, 3/4 in
Pump curve usedSource ↗
Curve B

Active Aqua AAPW550

Approximate manufacturer-chart digitization; marginal verdicts are intentionally conservative.

Zero-head flow529 GPH
Max head7.7 ft
Power33 W
Connections1/2 in, 3/4 in
Pump curve usedSource ↗
Curve B+

Active Aqua AAPW800

Manufacturer publishes 800 GPH, 58 W and 4.1 psi rated output pressure.

Zero-head flow800 GPH
Max head9.5 ft
Power58 W
Connections1/2 in, 3/4 in, 1 in
Pump curve usedSource ↗
Curve B

Active Aqua AAPW1000

Curve is conservative interpolation anchored to manufacturer 1,000 GPH and 4.9 psi output-pressure data.

Zero-head flow1000 GPH
Max head11.3 ft
Power92 W
Connections3/4 in, 1 in
Pump curve usedSource ↗

Why pump pages show curves, not just maximum GPH

The zero-head number on a pump box is not what reaches a cold plunge chiller. ChillSizer models the operating point after hose, fittings, filter and chiller resistance.

Read the curve

Flow falls as required head rises. Multiple curve points are more useful than a single rated GPH number.

Reduce restriction first

Larger hose and lower-loss filtration can recover flow without simply adding pump watts.

Include pump heat

Submerged pumps add most of their electrical input to the water as heat; the thermal engine accounts for it.

Read pump sizing guideOpen plumbing hub