How should I compare DC aquarium variable-frequency pumps when maximum flows use different heads?

Compare the pumps at the same operating point, not by their advertised maximum flow. Determine the system flow requirement and total head, including elevation and losses through pipe, fittings, valves, filters, and the return path. Then read each manufacturer’s flow-head curve at that point. A maximum-flow value measured near zero head cannot establish performance in a connected aquarium system. For a fair comparison, request the curve’s test conditions and tolerances, and ask for input power, efficiency where available, speed or controller range, noise, operating temperature, and installation limitations. Confirm whether the figures represent a duty point, a range, or only a headline maximum. Also check the outlet and control configuration against the aquarium’s plumbing and filtration. Send Jinwa the target flow, head, voltage, frequency, installation, and duty so the team can recommend a current DC aquarium variable-frequency model and a sample verification plan.