Growonix EX400 Reverse Osmosis Filter - 400 GPD - 17 GPH - 2:1 Ratio - 3/8-in Feed

Low-Waste RO Water for Reservoirs - 400 GPD Rated

Mineral-heavy tap water makes nutrient mixes hard to control. This reverse osmosis system filters feed water through a sediment filter, a coconut carbon filter and a membrane. It runs at a 2:1 system ratio and is rated at 96% nominal salt rejection.

At 17 gallons per hour of permeate, this unit suits regular indoor growers who refill reservoirs often, and small commercial rooms that want a compact, wall-mounted RO system.

Key Features & Benefits

• 2:1 system ratio — produces permeate while limiting concentrate water.
• Included pre-filters — an Eco Green coconut carbon filter and a High Flow pleated sediment filter come in the box.
• Auto shutoff valve — shuts the system off automatically when used with a float valve.
• Liquid-filled gauges — 2.5-in stainless steel gauges let you check pressure at a glance.
• Powder coated steel brackets — electrogalvanized brackets hold the unit in place.

Who Should Use Growonix EX400

Growers who mix their own nutrient solutions and want a consistent, low-TDS starting water will find it useful. It suits hobby gardeners and small commercial operations alike, provided the feed water meets the limits below.

About Growonix EX400

The Growonix EX400 is a reverse osmosis filter rated at 400 gallons per day, or 17 gallons per hour. It uses a 3/8-in feed tube and 1/4-in permeate and concentrate tubes. It measures 14 x 7 x 18 in and ships at 14 lb.

Frequently Asked Questions

Q: What feed water can it handle?
A: Feed TDS must stay under 2000 ppm, with pressure of 45 to 80 psi. Feed temperature must be 40 to 90 °F, and hardness must be 0 gpg. Continuous pH should stay between 5 and 11.

Q: Do I need extra pre-filters?
A: The included sediment and carbon filters are the stated pre-filtration, so no additional pre-filters are listed as needed. Chloramine removal needs a KDF85 carbon filter.

Q: How long does the carbon filter last?
A: Its stated capacity is 8,000 total gallons of chlorine or chloramine removal. At a 2:1 ratio, that works out to 3,000 gallons of RO water.

Q: What does the 2:1 system ratio mean?
A: It describes the balance between purified water and concentrate water the system produces. The 2:1 figure is the manufacturer's stated ratio.

Q: Can I leave it running unattended?
A: The auto shutoff valve gives automatic shutoff when the system is paired with a float valve. Check your setup and local requirements before leaving it unattended.

Q: What does SDI under 3 mean?
A: SDI is the silt density index, a measure of fouling potential in feed water. Keep it below 3 to protect the membrane.