Water Treatment Chemistry
RO Pretreatment & Membrane Treatment
From pretreatment to membrane protection, Mid South Chemical provides high-performance, NSF/ANSI/CAN 60 certified chemistry to help you maximize RO system performance, reduce downtime, and extend membrane life.
RO Pretreatment – Dechlorination
Chlorine and other oxidants can damage thin-film composite (TFC) RO membranes. These NSF/ANSI/CAN 60 listed sodium bisulfite products are used to dechlorinate feedwater ahead of the membrane. Dose to residual, then confirm chlorine is fully quenched before the elements.
Sodium Bisulfite 20%
Dechlorinator & Antioxidant
NSF/ANSI/CAN 60 listed dechlorinator for RO pretreatment. Use ahead of TFC membranes to remove free chlorine; confirm residual sulfite and chlorine before permeate use.
Sodium Bisulfite 30%
Dechlorinator & Antioxidant
NSF/ANSI/CAN 60 listed dechlorinator for RO pretreatment. Use ahead of TFC membranes to remove free chlorine; confirm residual sulfite and chlorine before permeate use.
Sodium Bisulfite 40%
Dechlorinator & Antioxidant · NSF/ANSI/CAN 60 Listed
NSF note: These products contain sulfite. Sulfites can cause allergic reactions in sulfite-sensitive individuals. The maximum recommended allowable residual sulfite in finished drinking water is 100 ppb (0.1 mg/L).
RO Antiscalants – Find the Right Product for Your System
Not sure which antiscalant is right for your RO application?
Use our interactive selection tool to evaluate your feedwater chemistry, recovery and potential scaling risks, and get a recommended Mid South Chemical antiscalant.
NSF/ANSI/CAN 60
RO Antiscalant Selection Tool
Find the right Mid South Chemical antiscalant for your RO feedwater chemistry.
Maximize performance.
Already experiencing membrane fouling?
Offline cleaners are for fouled membranes taken out of service — not for online feed treatment.
Only if the membrane is fouled and taken offline:
- RO 1306 — acid cleaner
- RO 1307 — alkaline cleaner
- RO 1324 — stubborn acid + pH-clear rinse
Need a full RO water analysis?
Send your feedwater analysis to Mid South Chemical. Our technical team will review recovery, scaling potential, and starting dose.
REQUEST TECHNICAL REVIEWRO Antiscalants
Our RO antiscalants are designed to control scale and minimize fouling, helping you achieve higher recovery, longer run times, and lower operating costs. All products are NSF/ANSI/CAN 60 certified.
| Trade Designation | Product Function | Max Use | Description |
|---|---|---|---|
| RO 1300 | Reverse Osmosis Antiscalant | 11 mg/L | A high-performance antiscalant formulated to prevent scale, iron, and general fouling in RO systems, certified for use up to 11 mg/L to optimize membrane efficiency and longevity. |
| RO 1301 | Reverse Osmosis Antiscalant | 21 mg/L | An advanced antiscalant providing excellent scale inhibition and dispersion, certified for use up to 21 mg/L, ideal for protecting RO membranes in challenging feedwater conditions. |
| RO 1302 | Reverse Osmosis Antiscalant | 9 mg/L | A heavy-duty antiscalant designed for demanding applications, effectively controlling scale, iron, and fouling, certified for use up to 9 mg/L to maintain high RO system performance. |
| RO 1303 | Reverse Osmosis Antiscalant | 10 mg/L | A specialized antiscalant with superior silica and magnesium silicate inhibition, certified for use up to 10 mg/L, ensuring long-term RO membrane protection and reduced cleaning frequency. |
| RO 1304 | Reverse Osmosis Antiscalant | 18 mg/L | An advanced antiscalant effective against silica and magnesium silicate scale, certified for use up to 18 mg/L in RO and distillation systems for reliable, scale-free operation. |
| RO 1305 | Reverse Osmosis Antiscalant | 40 mg/L | A robust, high-dose antiscalant formulated to prevent a broad range of scales and fouling, certified for use up to 40 mg/L when more NSF dose headroom is needed. |
| RO 1321 | Reverse Osmosis Antiscalant | 20 mg/L | A versatile antiscalant providing reliable scale control and membrane protection, certified for use up to 20 mg/L, suitable for a wide range of RO system conditions. |
RO Membrane Cleaners
When fouling occurs, our high-performance membrane cleaners help restore productivity and extend membrane life. Products include alkaline, acidic, and specialized cleaning chemistries.
Off-line use only. These cleaners are formulated for cleaning reverse osmosis membranes taken out of service. They must be thoroughly flushed out prior to returning the system to potable service, following manufacturer instructions.
| Trade Designation | Product Function | Max Use | Description |
|---|---|---|---|
| RO 1306 | Membrane Cleaner (acid) | NA (off-line) | A specialized off-line acid membrane cleaner designed to remove organic and inorganic foulants from RO membranes, restoring flux and performance when used according to instructions and followed by complete flushing. |
| RO 1307 | Membrane Cleaner (alkaline) | NA (off-line) | An effective off-line alkaline cleaner targeting scale, metal oxides, and biological deposits on RO membranes. Thorough rinsing is required before resuming potable water production. |
| RO 1324 | Membrane Cleaner | NA (off-line) | A powerful off-line RO membrane cleaner formulated to dissolve and remove stubborn foulants, helping restore original membrane efficiency with complete flushing essential prior to service. |
Need Help with Your RO Application?
Send us your water analysis and operating data for a technical review. Our team can provide product recommendations and system support.