DI versus RO
Which system should you choose?
The standalone Ultra S is the lower-cost, more compact option. It’s a good fit for occasional water-fed pole work, smaller jobs or where water supplies have low levels of total dissolved solids (TDS). It also produces no reject water.
The Nano RO with Ultra S included makes more sense if you regularly clean in hard-water areas, use larger volumes of pure water or find yourself replacing resin frequently. It costs more upfront and adds a pre-filter and membrane to maintain. You’ll also need somewhere to discharge the reject water from the membrane. If you’re weighing up the cost, start with how often you currently change resin and what you spend on it over a typical year.
If you’re getting through resin packs quickly in hard-water areas, the new Unger HydroPower Nano RO could help you get more pure water from each pack. The model we stock at The Windowclean Centre includes the HydroPower Ultra S DI filter and runs on mains water pressure, so there’s no pump or electrical connection to set up on site.
What does the Nano add to the Ultra S?
The HydroPower Ultra S is a compact, resin-only filter. Tap water passes directly through a deionisation (DI) resin pack, which removes dissolved minerals so you can rinse glass with pure water. The Nano uses the same Ultra S filter as its final stage and adds two stages ahead of it.
- Pre-filter. Removes sediment and chlorine to help protect the membrane.
- Nano membrane. Reduces the amount of dissolved minerals reaching the resin.
- HydroPower Ultra S DI filter. Removes the remaining dissolved minerals. The built-in TDS meter lets you check the outgoing water quality before it reaches your water-fed pole.
Why it matters in hard-water areas
With a standalone Ultra S, the resin has to remove all the dissolved minerals in the incoming water. On a busy round in a hard-water area, that can mean frequent resin changes. By doing much of that work upstream, the Nano helps each resin pack last longer. Unger quotes up to 14 times as much use from a resin pack with the Nano membrane and Flow Optimizer. How much extra use you get will depend on your water supply and how you run the system.
The Flow Optimizer lets you balance water output and resin use, while the inlet gauge shows the water pressure available at the job. Unger quotes an output of approximately 100–260 litres per hour at 3.5 bar and 21°C, depending on the dial setting and with no back pressure at the outlet. The Nano also has large wheels and built-in pole holders to help you move it around on site.
Whichever system you choose, the Unger systems will give you a sparkling result.