Choose your route
System comparison
The best RODI systems for UK homes
Compare current RO and RO/DI routes by output, pressure needs, monitoring, price and replacement burden.
Maintenance cost
RODI stages explained: what they do and when to replace them
Understand what each stage does, when it needs changing and which running costs are easy to miss.
Sizing
What size RODI unit do you need?
Turn water-change volume, evaporation and turnaround time into a sensible membrane size.
Water quality
TDS and source water for reef tanks
Use feed, post-RO and post-DI readings to spot membrane or resin problems before they reach the tank.
Salt mixing
How to mix saltwater for a reef tank
A repeatable UK-friendly workflow for RO/DI water, salinity, temperature, mixing and storage.
THE WATER RULE
RODI is a control system, not a magic label.
Reverse osmosis removes most dissolved solids; the deionisation stage polishes what remains. A final 0 ppm TDS reading is a useful operating target, but you still need to monitor the stages, change consumables and mix salt to a measured salinity.