FOR REEF KEEPERS

Zero-TDS water for thriving reef tanks.

Reef tanks demand the purest water you can give them — phosphate, silicate, copper, and nitrate from tap water feed algae, crash corals, and starve calcium reactors. Our RO/DI systems give reefkeepers a true 0 TDS feed so every parameter you dose is intentional.

  • Founded 198540 years of reef-grade water
  • Built in Tempe, AZAssembled and tested by hand
  • In-house membranesHand-tested SpectraSelect
  • Lifetime supportReal engineers on the phone
REEF-READY SYSTEMS

RO/DI systems sized for reef tanks.

From nano cubes to 500-gallon mixed reefs.

View all reef systems

Why RO/DI for reef

RO alone is not enough for reef tanks. A standard RO system removes 95–99% of dissolved solids — great for drinking water, not good enough for reef tanks. The remaining 1–5% includes the phosphates, silicates, and heavy metals that fuel nuisance algae and stress corals.

RO/DI adds a deionization stage after the RO membrane that brings TDS to 0 ppm. That's the difference between water that looks clean and water that tests clean.

SpectraPure pioneered hand-tested RO/DI for reefkeepers in 1985. Our SuperDI MaxCap and SilicaBuster cartridges remove the silica that standard DI resin misses.

Sizing guide for reefkeepers

  • Nano (10–40 gal): 90 GPD system is plenty. Most reefkeepers in this range want a 4 or 5-stage with auto-shutoff.
  • Mid-size (40–120 gal): 90–150 GPD. Look for the MaxPure or MaxCap 90 GPD with a holding tank.
  • Large (120–300 gal): 150–200 GPD. The MaxCap 1:1 series at 200 GPD pays back in water bill savings within a year.
  • Large (300+ gal) or multi-tank: 200+ GPD with booster pump. Consider the MaxCap 1:1 or a CSPDI-300.

Every system here is rated at stabilized output — the GPD you'll actually see after the membrane has run for a few hours. Not the inflated day-one numbers other brands quote.

For freshwater drinking, RO is fine. For reef, the silicate and phosphate that pass through a standard RO membrane will fuel diatoms, hair algae, and dinoflagellates. RO/DI brings TDS to 0 ppm — reef-safe.

Sediment and carbon pre-filters: every 6 months. RO membrane: 2–3 years depending on feed TDS. DI resin: when your TDS meter reads above 0 (typically 6–12 months for most reefkeepers).

MaxPure uses standard waste ratios (3:1 or 4:1) — simpler, less expensive, great for most reefkeepers. MaxCap uses our patented 1:1 waste ratio with an integral booster pump — same output, one-quarter the wastewater. Pays back in water savings if you make more than 20 gallons of RO/DI per week.

Standard RO systems need 50–60 psi feed pressure. If your house is below that, or you're on a well, the MaxCap with integral booster pump handles down to 25 psi. We can also spec a standalone booster pump for any system.

We ship every SpectraPure system within the continental US. Free shipping on full systems $150+. International — contact us for a freight quote.

USED BY REEFKEEPERS

From nanos to 500-gallon mixed reefs.

"Switched my 180-gal mixed reef to SpectraPure RO/DI three years ago. Zero algae since."
M. Patel — Reef tank, 180 gal mixed

0 TDS, 0 phosphate

"The 1:1 MaxCap paid for itself in a year on water bill alone. And the support team actually picks up the phone."
J. Hernandez — Reef tank, 75 gal SPS

200 GPD, 1:1 waste

"Tried three other brands. Only SpectraPure consistently reads 0 ppm out of the DI."
K. Schultz — Reef tank, 240 gal LPS

0 ppm DI output