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Gallons Per Day

What is GPD (Gallons Per Day)?

GPD stands for Gallons Per Day. The daily permeate flow rate of an RO element under standard test conditions. The number after the dash in residential model names (e.g. RE-1812-75 produces 75 GPD).

  • BWRO

    RO designed for feed waters with TDS roughly 500–10,000 ppm — typical of tap water, wells, and many industrial streams.

  • SWRO

    RO designed for seawater feed (~35,000 ppm TDS), running at high pressure (~800 psi) with very high salt rejection (>99.7%).

  • TDS

    The total mass of all dissolved minerals and salts in a water sample, in mg/L or ppm. The single most important number for sizing an RO system.

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