GrowMax De-Ionization Filter Kit – DI Resin Filter

Take your RO water down to true zero

The GrowMax De-Ionization Filter Kit, in 10" and 20" sizes, is a polishing stage for reverse osmosis systems, fitted into the RO unit's output line to strip out the last dissolved solids a standard membrane leaves behind. Where a good RO system typically gets you down to a handful of ppm, a DI stage takes that water to genuine 0 ppm / 0.0 EC — as pure as feed water gets.

What's Included

• 10" or 20" Filter Housing, to match the size you choose
• De-Ionization Resin Cartridge

Key Benefits

• Takes RO output to 0 ppm / 0.0 EC, removing dissolved solids a membrane alone can't catch
• Fits directly into the RO system's output pipe as an additional stage, not a standalone unit
• Standard 10" or 20" housing, straightforward to plumb in and service — the 20" takes a longer resin cartridge for higher-throughput set-ups
• Gives full control over your base nutrient solution, since every point of EC in the feed water is now down to what you add yourself

Why bother with true zero?

Tap and even RO water can carry a residual EC that's invisible until you're trying to dial in an exact nutrient strength — a few ppm of unknown minerals in the feed water throws off every ratio you're working to. Starting from a genuine 0.0 EC baseline means the only thing in the tank is what you actually put there.

How to Use

Plumb the housing into the output line of an existing reverse osmosis system, after the RO membrane stage, so only already-filtered water passes through the resin. Check output EC periodically and replace the resin cartridge once it stops holding at 0 ppm.