Aqua Medic Reverse Osmosis Membrane – 75 GPD

This high-efficiency reverse osmosis  75 GPD (RO) membrane is designed to produce up to 75 gallons (≈ 285 litres) of purified water per day under standard operating conditions. It’s ideal for aquarium and reef keepers who require consistently pure source water for marine or freshwater systems.

The membrane removes up to 95–98 % of dissolved solids and other impurities, including silicates, nitrates, phosphates, heavy metals and chlorine by-products, giving you a stable, low-TDS feed water for sensitive aquatic life.

Key Features

• High production rate: up to 75 gallons per day (GPD) or ~285 L/day under 60 psi and 25 °C feedwater conditions.

• High rejection rate: typically 95–98 % TDS rejection (varies depending on feedwater temperature, pressure and quality).

• Industry standard size: 11.75" × 1.8" (fits most standard RO housings).

• Durable construction: thin-film composite (TFC) membrane designed for long service life when properly maintained.

• Compatible with Aqua Medic and other standard RO systems.

Maintenance Guide

1. Replace Pre-Filters

• Frequency: every 6–12 months (or sooner with poor incoming water quality).

• Reason: sediment and carbon pre-filters capture particles and neutralize chlorine before it reaches the membrane. A neglected pre-filter can clog or allow chlorine to damage the membrane’s thin film layer.

2. Flush the Membrane Regularly

• How: use a manual or automatic flush valve to run unpressurized feed water across the membrane for a few minutes.

• Frequency: about once a week or after each use, especially if your feed water has high TDS or hardness.

• Reason: helps remove accumulated solids and prevent scaling, which keeps the rejection rate high and extends membrane life.

3. Monitor Product Water Quality

• Tool: use a handheld or inline TDS meter.

• Normal output: about 95–98 % TDS rejection compared to the feedwater.

• Action: if the product water TDS climbs significantly above normal, it may indicate fouling or a worn membrane.

4. Keep the Membrane Wet

• Do not let it dry out: prolonged dry storage can damage the membrane structure.

• If not using for weeks or months: store in its sealed bag with preservative solution or keep the system filled with water and sealed to prevent bacteria growth.

5. Replace When Needed

• Typical lifespan: 2–3 years under normal aquarium use (varies by feedwater quality, pre-filter maintenance, and flushing frequency).

• Signs it’s time to replace:

  • consistently high TDS in the product water

  • noticeably reduced flow rate

  • visible fouling, scaling, or bad odour

Tips for Best Performance of the membrane for reverse osmosis systems 75 GPD 

• Operate at the manufacturer’s recommended pressure (usually around 50–80 psi) for maximum output and rejection.

• Keep feedwater between 4 °C and 38 °C; hot water can permanently damage the membrane.

• Always install proper sediment and carbon pre-filters ahead of the membrane.

• Sanitize or replace housings and tubing periodically to avoid bacterial contamination.