RODI

Definition

RODI (Reverse Osmosis + Deionization) is a multi-stage water filtration process that produces ultra-pure water (0 TDS) for reef + planted aquarium use. Tap water contains chloramines, phosphates, copper, and other contaminants harmful to aquatic life; RODI strips them.

Practical use in aquariums

A typical 4-stage RODI unit: sediment filter → carbon block → RO membrane → DI resin. Test output with a TDS meter: 0 ppm = clean. RO membranes last 2-3 years; DI resin lasts 6-12 months depending on source water quality.

How RODI fits the bigger picture

Understanding RODI matters because it's connected to broader husbandry decisions: equipment selection compounds: skimper + return + dosing all need to match each other and the tank size.

Browse the Fast Aquatics care library for full husbandry tutorials covering RODI in context.