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Why RO Plants Need Antiscalant, and When You Can Skip It
Quick answer: As RO concentrates the minerals in water, hard salts such as calcium carbonate can crystallise on the membrane as scale, cutting output and raising TDS. Antiscalant, dosed in small amounts before the membranes, keeps those minerals in solution. Hard or high-TDS borehole water usually needs it; soft, low-TDS water often does not.
Key facts
- Scale blocks membranes: less water, higher TDS, early replacement
- Antiscalant keeps minerals dissolved as RO concentrates them
- Hard or high-TDS borehole water usually needs it
- Dosed by a small dosing pump before the membranes
On this page
Signs of scaling
- Output falls steadily even with new pre-filters.
- Product-water TDS creeps up.
- Feed pressure rises to keep the same output.
Do you need antiscalant?
| Water | Antiscalant |
|---|---|
| Hard borehole water, high TDS | Usually needed |
| Water already softened | Often not needed |
| Low-TDS municipal water | Often not needed |
RO stations with antiscalant dosing
H-Tech RO Vending Station 125 LPH with AntiscalantKSh 420,000
H-Tech RO Vending Station 250 LPH with AntiscalantKSh 540,000
H-Tech RO Vending Station 500 LPH with AntiscalantKSh 800,000
H-Tech RO Vending Station 1000 LPH with AntiscalantKSh 1,030,000| Product | Price |
|---|---|
| H-Tech RO Vending Station 125 LPH with Antiscalant | KSh 420,000 |
| H-Tech RO Vending Station 250 LPH with Antiscalant | KSh 540,000 |
| H-Tech RO Vending Station 500 LPH with Antiscalant | KSh 800,000 |
| H-Tech RO Vending Station 1000 LPH with Antiscalant | KSh 1,030,000 |
Current listed prices incl. VAT (updated 30 September 2026).
How it is dosed
A small dosing pump injects antiscalant after the cartridge filters, before the high-pressure pump and membranes, at the rate the chemical supplier specifies for your water.
Also read RO maintenance and water softeners.
Frequently asked questions
What does antiscalant do in RO?
It keeps hardness minerals dissolved so they do not form scale on the membranes.
Can a softener replace antiscalant?
A softener removes hardness and can reduce the need, but the right choice depends on your water analysis.
How do I know my membrane is scaled?
Output drops, TDS rises and feed pressure increases.
Do your RO stations include antiscalant dosing?
H-TECH RO vending stations are available with antiscalant dosing; see the table.