RO Antiscalant & Membrane Cleaning Chemicals
Zyax supplies RO antiscalants, membrane cleaning chemicals and RO support chemicals to plant owners, OEMs and maintenance contractors across India. The right antiscalant lets your reverse osmosis plant run at its designed recovery without scaling, and the right cleaner brings fouled membranes back to their rated flow.
- Manufacturer & supplier, Mumbai
- Send your water report, get a product recommendation
- Bulk packs, delivered across India
- Range
- Antiscalant, acid and alkaline membrane cleaners, non-oxidising RO biocide, SMBS, pH booster, food-grade remineralisation salts, antiscalant balls, citric acid
- Used in
- Industrial RO, packaged drinking water plants, hotels, hospitals, pharma, food and beverage, housing societies, domestic RO
- Forms
- Liquids in cans and drums; powders and salts in bags
- How we help
- Send your feed water analysis and plant details; we recommend the product and dose
What does an RO antiscalant do?
As water passes through an RO membrane, the salts left behind become more and more concentrated. Near the end of the membrane, minerals such as calcium carbonate, calcium sulphate, barium and strontium sulphate, calcium fluoride and silica pass their solubility limit and start to form hard scale on the membrane surface. Scale blocks the membrane, so output falls, pressure rises and salt passage goes up.
An antiscalant is dosed continuously into the feed water, upstream of the cartridge filter and high-pressure pump. At a few parts per million it works in three ways:
- Threshold inhibition: it keeps scaling salts dissolved beyond their normal limit.
- Crystal modification: any crystals that do form stay small and distorted, so they cannot build a hard layer.
- Dispersion: fine particles stay suspended and leave with the reject stream.
This lets a plant run at a higher recovery (more permeate from the same feed) with less reject water, fewer cleanings and longer membrane life.
Our RO chemical range
| Product | What it does | Where and how it is used |
|---|---|---|
| RO antiscalant | Controls carbonate, sulphate and fluoride scale; specialty grades extend silica limits; tolerates low levels of iron and colloids | Continuous dosing into RO feed, before the cartridge filter, with a dosing pump |
| Acidic membrane cleaner | Dissolves carbonate scale and metal oxides such as iron | Clean-in-place (CIP) when scale is the problem |
| Alkaline membrane cleaner | Removes organic fouling, biofilm, silt and colloids | Clean-in-place, usually the first step of a cleaning |
| Non-oxidising RO biocide | Controls bacterial growth and biofouling without damaging polyamide membranes | Shock dosing or during cleaning |
| Sodium metabisulphite (SMBS) | Removes free chlorine before it reaches the membrane; used to preserve membranes in storage | Continuous dosing after chlorination and before RO |
| pH booster | Raises the pH of RO permeate | Post-treatment of drinking water |
| Remineralisation salts (food grade) | Sodium bicarbonate, potassium bicarbonate and magnesium sulphate add back minerals and taste | Packaged drinking water and post-RO treatment |
| RO antiscalant balls | Slow-release scale control for small systems | Domestic and small commercial RO units |
| Citric acid | Mild acid cleaning | Small RO units and pre-filters |
When should you clean RO membranes?
Membrane makers commonly advise cleaning when any one of these happens, compared with the plant's baseline after start-up or the last cleaning:
- Normalised permeate flow drops by about 10 to 15%.
- Normalised salt passage rises by about 5 to 10%.
- The pressure drop across a stage rises by about 10 to 15%.
Waiting longer makes fouling harder to remove. A typical cleaning uses an alkaline cleaner first to strip organic and biological fouling, then an acid cleaner for scale and metal oxides, with a thorough rinse between steps. Always follow your membrane manufacturer's pH and temperature limits.
Before you dose any oxidising chemical such as chlorine or hypochlorite, remember that polyamide RO membranes are damaged by free chlorine. That is why SMBS is dosed upstream of the membranes, and why we offer a non-oxidising biocide for RO systems.
How to choose the right antiscalant
No single antiscalant suits every water. The choice depends on what is in your feed water and how hard you push recovery. Share these details and we will recommend a product and starting dose:
- Feed water analysis: TDS, calcium, magnesium, alkalinity, sulphate, silica, iron, barium or strontium if known, and pH.
- Plant details: capacity (m³/hr or LPH), recovery, number of stages, membrane make and model.
- Current problems: output loss, rising pressure, frequent cleaning, or high TDS in permeate.
- Our recommendation: the product, a starting dose and pack size, and the cleaners you should keep on hand.
Who uses our RO chemicals
- Packaged drinking water plants
- Hotels and resorts
- Hospitals and dialysis water
- Pharmaceutical purified water
- Food, dairy and beverage
- Textile and dyeing units
- Power and boiler feed
- Housing societies and commercial buildings
- ZLD and effluent RO
- Water treatment OEMs and AMC contractors
Why buy RO chemicals from Zyax
- One supplier for the whole RO system: pre-treatment coagulants, SMBS, antiscalant, cleaners, biocide and post-treatment minerals.
- Advice based on your water: send your water report and we recommend what to use, rather than selling one product for every plant.
- Bulk and small packs: from domestic RO units to large industrial plants, delivered across India from Mumbai.
Grades and specifications
Typical values for each grade we supply. Technical data sheet and safety data sheet available on request.
Low pH liquid antiscalant (broad spectrum)
Our standard grade for most RO plants. Works with chlorine present and hardness up to 1,000 ppm, controls silica up to 150 ppm. Phosphate-free.
| pH (as such) | 2.5 to 3.5 |
|---|---|
| Appearance | Pale yellow liquid |
| Solubility in water | Completely soluble |
| Solid content | 33% to 34% w/w |
| Specific gravity | 1.05 to 1.08 |
| Standard packs | 25 kg, 10 kg and 5 kg carboys |
| HS code | 38249022 |
High pH liquid antiscalant
For feed water with high pH (up to 10) and alkalinity (up to 750 ppm). Hardness up to 1,000 ppm, silica up to 150 ppm. Also inhibits calcium sulphate.
| pH (as such) | 9.5 to 10.5 |
|---|---|
| Appearance | Pale yellow liquid |
| Solubility in water | Completely soluble |
| Solid content | 33% to 34% w/w |
| Specific gravity | 1.07 to 1.11 |
| HS code | 38249022 |
High silica liquid antiscalant
For borewell water with silica up to 300 ppm. Hardness up to 1,000 ppm, pH up to 10, alkalinity up to 750 ppm.
| pH (as such) | 2.5 to 3.5 |
|---|---|
| Appearance | Pale yellow liquid |
| Solubility in water | Completely soluble |
| Solid content | 33% to 34% w/w |
| Specific gravity | 1.05 to 1.07 |
| HS code | 38249022 |
Powder antiscalant with silica control
High-strength powder for preparing the dosing solution on site. Controls carbonate, sulphate, fluoride and silica scale, and iron and aluminium hydroxides.
| Appearance | White powder |
|---|---|
| Solubility in water | Completely soluble |
| Standard packs | 25 kg |
| HS code | 38249022 |
Economy liquid antiscalant
Cost-effective grade for hardness up to 900 ppm and silica up to 100 ppm. Disperses calcium phosphate, carbonate, silicate and iron oxide.
| pH (as such) | 2.5 to 3.5 |
|---|---|
| Appearance | Pale yellow liquid |
| Solubility in water | Completely soluble |
| Solid content | 33% to 34% w/w |
| Specific gravity | 1.05 to 1.08 |
| Standard packs | 25 kg carboy |
| HS code | 38249022 |
RO Antiscalants & Membrane Cleaners: product range
Each product line has its own page with uses, dosing guidance and FAQs.
- RO Membrane Cleaners (Acid and Alkaline)
- Non-Oxidising RO Biocide
- Sodium Metabisulphite (SMBS)
- RO pH Booster
- Remineralisation Minerals for Drinking Water
- RO Antiscalant Balls
Frequently asked questions
What is an RO antiscalant?
An RO antiscalant is a chemical dosed into the feed water of a reverse osmosis plant at a few parts per million. It keeps scaling minerals such as calcium carbonate, calcium sulphate and silica dissolved, so they do not form hard scale on the membranes.
Where is antiscalant dosed in an RO plant?
Antiscalant is dosed continuously with a dosing pump into the RO feed line, after the media and carbon filters and before the cartridge filter and high-pressure pump, so it is fully mixed before the water reaches the membranes.
How much antiscalant should I dose?
The dose depends on your feed water chemistry, recovery and the antiscalant used. Send us your water analysis and plant details and we will recommend a starting dose.
Is an antiscalant needed if I have a water softener?
A softener removes calcium and magnesium, which greatly reduces carbonate and sulphate scale risk, but it does not remove silica, and hardness can leak through if regeneration slips. Many plants still use an antiscalant after a softener, especially at high recovery or high silica.
Which cleaner should I use first, acid or alkaline?
For most fouled membranes an alkaline cleaning is done first to remove organic and biological fouling, followed by an acid cleaning for scale and metal oxides. If the plant has only scale and no organic fouling, an acid cleaning alone may be enough.
Why is SMBS used before an RO membrane?
Polyamide RO membranes are damaged by free chlorine. Sodium metabisulphite (SMBS) is dosed after chlorination to neutralise the chlorine before the water reaches the membranes. It is also used in solution to preserve membranes during storage.
Do you supply chemicals for domestic RO purifiers?
Yes. We supply antiscalant balls for small RO units and food-grade minerals for remineralising RO water, as well as chemicals for large industrial plants.
What is the difference between antiscalant and antifoulant?
The terms are often used loosely. An antiscalant targets mineral scale such as carbonates, sulphates and silica. An antifoulant or dispersant helps keep iron, colloids and organic matter from depositing. Many RO antiscalants combine both actions; a biocide is still needed for biological fouling.
Can antiscalant be used in drinking water RO plants?
Yes, when the antiscalant is a grade meant for drinking water plants and is dosed correctly. Tell us that your plant makes drinking water and we will recommend an appropriate product.
What details do you need to recommend an antiscalant?
Your feed water analysis (TDS, hardness, alkalinity, sulphate, silica, iron and pH), plant capacity, recovery, number of stages and membrane make. You can WhatsApp us a photo of your water report.
Get a quote for RO antiscalant and membrane cleaning chemicals
Tell us what you are treating and how much you use. Send your water or effluent analysis if you have one, and we will recommend the right product and pack size.
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