Large selection of replacement water filters, reverse osmosis membranes, testing kits and water filter system repair parts. From one water filter or membrane to case quantity discounts.

LOW PRICES and FAST SHIPPING SINCE 1999 !

99.5% Of All Items In Stock For Same Day Shipping!

Harmsco Water Filters ®

Harmsco Water Filters ®

Harmsco ® Replacement Water Filters & WaterBetter Replacement Sediment Filters
Page
  1. Pro Products Sani System Sanitizer
    Pro Products Sani System Sanitizer
    Pro Products Sani System Sanitizer. 0.25 or 0.5 fl. oz. concentrate. Sani-System ® Pro Products is proud to introduce Sani-System, the first and only EPA product approved for sanitizing water softeners, RO units and Water Coolers. Sani System is proven to kill 99.9% of E. coli, E. coli O157:H7, Staphylococcus aureus, Listeria monocytogenes and other harmful bacteria. It does not use chlorine, other oxidizers or acids that can harm water softener equipment parts. Use is simple; each dose comes in a pre-measured pouch. Just cut, pour and regenerate softener. No measuring, No mess! Sanitizing Equipment! Applications Interior Surfaces of Water Softeners, Reverse Osmosis (RO) Units, Ice Machines, Water Coolers, Water Holding Tanks and Pressure Tanks. Sani-System is now NSF certified! This is the best sanitizing solution available anywhere! Stock up and save. Learn More
    $7.99 Special Price $4.99 As low as $2.49
  2. TDS Meter - Test For Total Dissolved Solids In Water - Reverse Osmosis Membrane Tester - TDS Meter
    TDS Meter - Test For Total Dissolved Solids In Water - Reverse Osmosis Membrane Tester - TDS Meter
    TDS Meter - Tester. The Only Way To Know If Your Reverse Osmosis RO Membrane Is Performing Correctly - Tests for TDS - Total Dissolved Solids. A Must For All RO System Owners. Compare Incoming Feed Water To Treated Water - Replace Membrane If Less Than 80% of TDS Is Being Removed - The lower the TDS level in the water, the more efficiently your body's cells actually get hydrated by the water that you drink. The higher the TDS levels in the water, the greater the probability of harmful contaminants that can pose health risks or hinder the absorption of water molecules on the cellular level. Simple to use for Reverse Osmosis membrane monitoring. We really like this tester and think that anyone who wants to know about the quality of their water should have one of these TDS Meter Testers to monitor their RO membrane. Learn More
    $49.99 Special Price $37.99 As low as $17.99
  3. TDS Meter Inline Water Tester DM1 - HM Digital Dual Mode Reading
    TDS Meter Inline Tester- Dual Mode Reading - Easily Installs Inline - Very Simple To Use
    TDS Meter - Dual Mode - Installs Inline - Check the TDS level with the push of a button. Now you can easily check to make sure the water from your reverse osmosis system is top quality. Measure the tap water coming in vs. the purified water going out of your system at any time. Very easy installation. FEATURES Displays TDS levels of the feed water and product water with in & out electrode probes. Highly efficient and accurate due to its advanced microprocessor technology. Auto-Off function conserves battery power. The unit shuts off automatically after 10 minutes of non-use. Comes equipped with John Guest Quick-Connect T-fittings as shown. Installs quickly and easily. SPECIFICATIONS Range: 0-9990 ppm Accuracy: ±2% Always know if your RO membrane is performing correctly! Learn More
    $49.99 Special Price $39.99 As low as $19.99
  4. Molykote-From DOw Corning- 111 Compound-6 Gram O-ring Silicone Lubricant & Sealant-Dow-111-5-gram-1000
    Dow Corning (Molykote) ® 111 6 gram O-ring Silicone Lubricant and Sealant - Be sure to lube your O-rings to help prevent leaks.
    Dow Corning/Molykote ® 111 6 gram O-ring Silicone Lubricant and Sealant - 6 gram pillow pack. (like a ketchup packet) Great O-ring sealant and lubricant. FDA and NSF approved. (Do Not Use Petroleum Jelly As It May Break Down O-rings Or Housings) This is the same premium grade silicone sealant and lubricant used in underwater photography cameras, scuba gear and other underwater applications that simply can't afford leaks. Why not use the best for your reverse osmosis or drinking water filtration system?

    Dow 111 Silicone MSDS Safety Sheet

    Learn More
    $5.99 Special Price $3.99 As low as $1.79
  5. Harmsco 801 HIF 0.35 sub micron Replacement Sediment Filter
    Harmsco 801 HIF 0.35 sub micron Replacement Sediment Filter
    Harmsco 801 0.35 micron HIF Replacement Sediment highly efficient filter cartridges made of pleated Polyester-PlusTM filter media for low pressure drop, high flow capability, increased contaminant removal, long filter runs, reusability and the lowest cost per gallon filtered. • Pleated design with up to 50% more surface area than competitive filters resulting in superior performance & increased contaminant removal • Longer filtration runs for fewer change-outs and less maintenance • Low pressure drop • Thermally bonded for longer usable life • FDA approved materials - NSF 61 certified • Engineered media for superior performance. Learn More
    $13.99 Special Price $8.99 As low as $7.69
  6. Harmsco ® HB-10-1-W 10 Inch 1 Micron Big Blue Water Filter
    Harmsco ® HB-10-1-W 10 Inch 1 Micron Big Blue Water Filter
    Harmsco ® HB-10-1-W 10 Inch Big Blue Water Filter - 9 3/4" Long by 4 1/2" diameter - 1 Micron Big Blue - 8 per case, sold individually. Made with a proprietary blend of Polyester-PlusTM filter media. Cleanable and reusable in most applications, individually shrink wrapped. Flow rates Up to 15 GPM (56 LPM). Order a case and save even more. Learn More
    $29.99 Special Price $19.99 As low as $16.99
  7. Harmsco ® HB-10-20W Big Blue Water Filter
    Harmsco ® HB-10-20W Big Blue Water Filter
    Harmsco ® HB-10-20W Big Blue Water Filter - 9 3/4" Long by 4 1/2" diameter - 20 Micron Big Blue - 8 per case, sold individually. Made with a proprietary blend of Polyester-PlusTM filter media. Cleanable and reusable in most applications; individually shrink wrapped. Flow rates Up to 15 GPM (56 LPM). Order a case and save even more. Learn More
    $29.99 Special Price $18.99 As low as $16.49
  8. Harmsco ® HB-10-5-W Big Blue 5 Micron Water Filter
    Harmsco ® HB-10-5-W Big Blue 5 Micron Water Filter
    Harmsco ® HB-10-5-W Big Blue 5 Micron Water Filter - 9 3/4" Long by 4 1/2" diameter - 5 Micron Big Blue - 8 per case, sold individually. Made with a proprietary blend of Polyester-PlusTM filter media. Cleanable and reusable in most applications; individually shrink wrapped. Flow rates Up to 15 GPM (56 LPM). Order a case and save even more. Learn More
    $29.99 Special Price $19.99 As low as $16.89
  9. Harmsco ® HB-20-1-W 20 Inch Big Blue Water Filter
    Harmsco ® HB-20-1-W 20 Inch Big Blue Water Filter
    Harmsco ® HB-20-1-W 20 Inch Big Blue Water Filter - 20" Long by 4 1/2" diameter - 1 Micron Big Blue - 4 per case, sold individually. Made with a proprietary blend of Polyester-PlusTM filter media. Cleanable and reusable in most applications; individually shrink wrapped. Flow rates Up to 130 GPM (113 LPM) Order a case and save even more. Learn More
    $49.99 Special Price $34.99 As low as $29.99
  10. Harmsco ® HB-20-20-W 20 Inch Big Blue Water Filter
    Harmsco ® HB-20-20-W 20 Inch Big Blue Water Filter
    Harmsco ® HB-20-20-W 20 Inch Big Blue Water Filter - 20" Long by 4 1/2" diameter - 20 Micron Big Blue - 4 per case, sold individually. Made with a proprietary blend of Polyester-PlusTM filter media. Cleanable and reusable in most applications; individually shrink wrapped. Flow rates Up to 130 GPM (113 LPM) Order a case and save even more. Learn More
    $43.99 Special Price $31.99 As low as $28.99
  11. Harmsco ® WB-1-W WaterBetter Replacement Sediment 1 Micron Water Filter
    Harmsco ® WB-1-W WaterBetter Replacement Sediment 1 Micron Water Filter
    Harmsco ® WB-1-W WaterBetter Water Filter - Replacement Sediment 1 Micron - 9 3/4" L x 2 3/4" D - Polyester - Pressure drop with Harmsco cartridges is exceptionally low due to our pleated design and increased filter area. 24 per case, sold individually. Order a case and save even more. Learn More
    $12.99 Special Price $7.99 As low as $5.99
  12. Harmsco ® WB-20-W WaterBetter Replacement Sediment 20 Micron Water Filter
    Harmsco ® WB-20-W WaterBetter Replacement Sediment 20 Micron Water Filter
    Harmsco ® WB-20-W WaterBetter Water Filter - Replacement Sediment 20 Micron - 9 3/4" L x 2 3/4" D - Polyester - Pressure drop with Harmsco cartridges is exceptionally low due to our pleated design and increased filter area. 24 per case, sold individually. Order a case and save even more. Learn More
    $12.99 Special Price $7.99 As low as $6.39
  13. Harmsco ® WB-5-W WaterBetter Replacement Sediment 5 Micron Water Filter
    Harmsco ® WB-5-W WaterBetter Replacement Sediment 5 Micron Water Filter
    Harmsco ® WB-5-W WaterBetter Water Filter - Replacement Sediment 5 Micron - 9 3/4" L x 2 3/4" D - Polyester - Pressure drop with Harmsco cartridges is exceptionally low due to our pleated design and increased filter area. 24 per case, sold individually. Order a case and save even more. Learn More
    $12.99 Special Price $7.99 As low as $6.29
  14. Harmsco ® H-8600-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8600-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8600-AM Antimicrobial Replacement Pool Water Filter Cartridge - Step up to Premium Antimicrobial Construction. Cross reference HA8OTC-3, Unicel #C-8600, Pleatco # PA 80 and Filbur # FC 1280. 17 1/2 inches height x 8 1/2 inches diameter. Learn More
    $139.99 Special Price $79.99 As low as $74.99
  15. Harmsco 921-5 WaterBetter Replacement Sediment 5 Micron 19 1/2 Inch Water Filter
    Harmsco 921-5 WaterBetter Replacement Sediment 5 Micron 19 1/2 Inch Water Filter
    Harmsco 921-5 Replacement WaterBetter Sediment 5 Micron 19 1/2 Inch Water Filter. White end caps. Learn More
    $19.99 Special Price $12.99 As low as $11.99
  16. Harmsco 931-20 WaterBetter Replacement Sediment 20 Micron 29 1/4 Inch Water Filter
    Harmsco 931-20 WaterBetter Replacement Sediment 20 Micron 29 1/4 Inch Water Filter
    Harmsco 931-20 WaterBetter Replacement Sediment 20 Micron 29 1/4 Inch Water Filter. Blue end caps. Learn More
    $38.99 Special Price $24.99 As low as $20.99
  17. Harmsco 931-5 WaterBetter Replacement Sediment 5 Micron 29 1/4 Inch Water Filterv
    Harmsco 931-5 WaterBetter Replacement Sediment 5 Micron 29 1/4 Inch Water Filterv
    Harmsco 931-5 WaterBetter Replacement Sediment 5 Micron 29 1/4 Inch Water Filter. White end caps. Learn More
    $38.99 Special Price $24.99 As low as $20.99
  18. Harmsco ® H-4326-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-4326-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-4326-AM Antimicrobial Replacement Pool Water Filter Cartridge - Step up to Premium Antimicrobial Construction. Cross reference RA25TC-3, Unicel C-4625 - C-4326, Pleatco PRB 25-IN, Filbur FC 4375 - FC 2375. 13 3/8 inches height x 4 15/16 inches diameter. Learn More
    $37.99 Special Price $26.99 As low as $23.99
  19. Harmsco ® H-4607 Replacement Water Filter Cartridge
    Harmsco ® H-4607 Replacement Water Filter Cartridge
    Harmsco ® H-4607 Pleated Replacement Water Filter Cartridge - For F120 & DR7. Repalces F120TC / C-4607 / PC7-120 Coleco with core. 5 sq.ft. 7 15/16" length x 4 1/4" diameter. Learn More
    $12.99 Special Price $7.99 As low as $6.29
  20. Harmsco ® H-4950 Replacement Water Filter Cartridge
    Harmsco ® H-4950 Replacement Water Filter Cartridge
    Harmsco ® H-4950 Replacement Water Filter Cartridge - Unicel cross reference # C-4950. RA50TC-3 & PRB50-IN. Rainbow 50 sq.ft. 13 3/8 inches height x 4 15/16 inches diameter. Learn More
    $38.99 Special Price $26.99 As low as $23.99
  21. Harmsco ® H-4950-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-4950-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-4950 Replacement Water Filter Cartridge - Unicel cross reference # C-4950. RA50TC-3 & PRB50-IN. Rainbow 50 sq.ft. 13 3/8 inches height x 4 15/16 inches diameter. Learn More
    $39.99 Special Price $28.99 As low as $26.99
  22. Harmsco ® H-6430 Replacement Water Filter Cartridge
    Harmsco ® H-6430 Replacement Water Filter Cartridge
    Harmsco ® H-6430 Replacement Spa Water Filter Cartridge - Replaces WA30TC-3, C-6430 & PWK30. Watkins 30 sq.ft. Fits all models starting from 1991. 10 1/2" height X 6" diameter. Learn More
    $36.99 Special Price $24.99 As low as $22.99
  23. Harmsco ® H-7447 Replacement Water Filter Cartridge
    Harmsco ® H-7447 Replacement Water Filter Cartridge
    Harmsco ® H-7447 Replacement Water Filter Cartridge - Replaces CX470-RE, C-7447 & PA50-SV. Hayward 50 sq.ft., Sta-Rite PRC50. Learn More
  24. Harmsco ® H-7477 Replacement Water Filter Cartridge
    Harmsco ® H-7477 Replacement Water Filter Cartridge
    Harmsco ® H-7477 Replacement Water Filter Cartridge - Hayward 75 sq.ft. Sta-Rite PRC 75 compatible. Replaces CX570-RE / C-7477 / PA75-SV. Learn More
    $99.99 Special Price $58.99 As low as $54.99
  25. Harmsco ® H-7487 Replacement Water Filter Cartridge
    Harmsco ® H-7487 Replacement Water Filter Cartridge
    Harmsco ® H-7487 Replacement Water Filter Cartridge - Replaces CX870-RE, C-7487 & PA100-N. Hayward 100 sq.ft.. 25 1/2 height x 6 7/8 diameter. Learn More
    $119.99 Special Price $72.99 As low as $69.29
  26. Harmsco ® H-7626 Replacement Water Filter Cartridge
    Harmsco ® H-7626 Replacement Water Filter Cartridge
    Harmsco ® H-7626 Replacement Water Filter Cartridge - Replaces HA25TC-3, C-7626 & PA25. Hayward CX250-RE 25 sq.ft. Learn More
    $39.99 Special Price $27.99 As low as $24.99
  27. Harmsco ® H-7656 Replacement Water Filter Cartridge
    Harmsco ® H-7656 Replacement Water Filter Cartridge
    Harmsco ® H-7656 Replacement Water Filter Cartridge - Replaces HA50TC-3, C-7656 & PA50. Hayward CX500-RE, 50 sq.ft. 19 3/4 height X 6 4/8 diameter. Learn More
    $79.99 Special Price $46.99 As low as $43.99
  28. Harmsco ® H-8409-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8409-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8409-AM Antimicrobial Replacement Water Filter Cartridge - Step up to Premium Quality Of Antimicrobial Construction. Replaces HA90TC-3, C-8409 & PA90. Hayward CX900 RE. 90 sq.ft. 17 5/16" height X 8 7/8" diameter. Learn More
    $129.99 Special Price $84.99 As low as $79.99
  29. Harmsco ® H-8412-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8412-AM Antimicrobial Replacement Water Filter Cartridge
    Harmsco ® H-8412-AM Antimicrobial Replacement Water Filter Cartridge - Replaces HA120TC-3, C-8412 & PA120. Hayward 120 sq.ft. CX1200-RE. #0296 Step up to Premium Antimicrobial Construction. You deserve the best. Learn More
    $129.99 Special Price $99.99 As low as $93.99
  30. Harmsco ® H-8600 Replacement Water Filter Cartridge
    Harmsco ® H-8600 Replacement Water Filter Cartridge
    Harmsco ® H-8600 Replacement Water Filter Cartridge - Replaces HA80TC-3, C-8600 & PA80 and Hayward CX800-RE. 75 sq.ft. 17 1/2 height X 8 1/2 diameter. Learn More
    $99.99 Special Price $67.99 As low as $62.99
Page
Be sure to check our Parts Department for important parts such as TDS Testers For Reverse Osmosis Membranes, Replacement Tanks, O-rings , Filter Housing Wrenches, Faucets, Pumps, Fittings, UV Systems and more parts for your reverse osmosis pure water filtration system.   View maintenance and servicing tips online at our Installation & Trouble shooting Guide.