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.

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Arrowhead Water Filters ®

Arrowhead Water Filters ®

O.E.M. Original Arrowhead Puritap ® Replacement Water Filters, Reverse Osmosis RO Membranes And Parts Made by Hydrotech

See Arrowhead Puritap Reverse Osmosis System Owner's Manual

  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. Air Pressure Gauge for Reverse Osmosis Water Accumulator Tanks -1000
    Air pressure gauge for reverse osmosis water accumulator tanks
    Air pressure gauge for reverse osmosis water accumulator tanks - Specially calibrated for reverse osmosis system tanks. Scale from 1 to 20 PSI. Large scale reading over small PSI range allows optimum accuracy. Just like car tires lose air pressure, so does the bladder of your reverse osmosis water accumulator tank. Improper tank air pressure will cause your system to operate improperly. This is a must for all reverse osmosis system owners. Learn More
    $24.99 Special Price $17.99 As low as $12.99
  5. 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
  6. HYDROTECH 33001056 - 75 GPD RO TFC Reverse Osmosis Membrane - 1000
    Hydrotech ® 33001056 75 GPD RO TFC Reverse Osmosis Membrane
    Hydrotech ® 33001056 75 GPD RO TFC Reverse Osmosis Membrane - Yellow body black or blue band. Learn More
    $139.99 Special Price $99.99 As low as $84.99
  7. Hydrotech ® HT-HTF Water Filter Wrench # 21401003
    Hydrotech ® HT-HTF Water Filter Wrench # 21401003
    Hydrotech ® E-VW-01 Filter Housing Spanner Wrench for Old Style 1230 HT-HTF Series Reverse Osmosis RO Systems. Also for the Aquifier series systems. For housing removal only. # 21401003. FOR THE NEW STYLE 1240 HT-HTF SEREIS REVERSE OSMOSIS SYSTEMS SELECT THE LARGE WRENCH (#21401240) IN THE DROP DOWN BOX. Learn More
    $9.99 Special Price $5.99 As low as $4.49
  8. Hydrotech ® S-FS-02 & Aquafier Sediment Replacement Water Filter # 41400008
    Hydrotech ® S-FS-02 & Aquafier Sediment Water Filter # 41400008
    Hydrotech ® S-FS-02 & Aquafier Sediment Water Filter. String Wound Depth Gradient. (Black End Caps) # 41400008 For HT & HTF Series Reverse Osmosis RO Systems. Learn More
    $17.99 Special Price $9.99 As low as $6.99
  9. Hydrotech ® S-FS-06 9 GPD CTA RO Membrane # 41400001 (#41400004)
    Hydrotech ® S-FS-06 9 GPD CTA RO Membrane # 41400001 (#41400004)
    Hydrotech ® S-FS-06 9 GPD CTA Reverse Osmosis RO Membrane Has Been Discontinued And Is No Longer Available. If You Order The S-SF-06 9 GPD CTA Membrane You Will Receive The Hydrotech S-FS-07 15 GPD TFC Membrane #41400004. (Blue/Red Band) # 41400001 For HT & HTF Series. Learn More
    $99.99 Special Price $69.99 As low as $54.99
  10. Hydrotech S-FS-07 - 15 GPD TFC RO Membrane #4140000 - 1000
    Hydrotech ® S-FS-07 15 GPD TFC RO Membrane # 41400004
    Hydrotech ® S-FS-07 15 GPD TFC Reverse Osmosis RO Membrane. (Green/Yellow Band, Yellow/Green Band or Blue/Yellow Band) # 41400004 For HT & HTF Series Systems. Learn More
    $99.99 Special Price $69.99 As low as $54.99
  11. Hydrotech ® S-FS-08 15 GPD CTA RO Reverse Osmosis Membrane # 41400002
    Hydrotech ® S-FS-08 15 GPD CTA RO Reverse Osmosis Membrane # 41400002 (#41400004)
    The Hydrotech ® S-FS-08 15 GPD CTA Reverse Osmosis RO Membrane Has Been Discontinued And Is No Longer Available. If You Order The S-SF-08 15 GPD CTA Membrane You Will Receive The Hydrotech S-FS-07 15 GPD TFC Membrane #41400004. (Green/Yellow Band, Yellow/Green Band or Blue/Yellow Band) # 41400002 For HT & HTF Series Systems. Learn More
    $99.99 Special Price $69.99 As low as $54.99
  12. HYDROTECH- S-FS-09 25 GPD TFC RO Reverse Osmosis Membrane #41400005, #33001068 - 1000
    Hydrotech ® S-FS-09 25 GPD TFC RO Membrane #41400005, #33001068
    Hydrotech ® S-FS-09 25 GPD TFC Reverse Osmosis RO Membrane. #41400005 (Green/Black Band), #33001068 (Yellow/Black Band or Blue/Black Band) For HT & HTF Series Systems. Learn More
    $99.99 Special Price $76.99 As low as $62.99
  13. HYDROTECH- S-FS-11 - GPD TFC RO Reverse Osmosis Membrane 41400006- 1000
    Hydrotech ® S-FS-11 35 GPD TFC RO Membrane # 41400006
    Hydrotech ® S-FS-11 35 GPD TFC Reverse Osmosis RO Membrane. (Green/Purple Band or Yellow/Purple and Green Bands) # 41400006 For HT & HTF Series Systems. Learn More
    $99.99 Special Price $79.99 As low as $64.99
  14. Hydrotech ® S-FS-13 , 41400010
    Hydrotech ® S-FS-13 & Aquafier Carbon Block Replacement Water Filter # 41400010
    Hydrotech ® S-FS-13 & Aquafier Carbon Block Water Filter. Lead Removal 1 Micron Filter. (Black End Caps) # 41400010 For Aquafier Reverse Osmosis RO Series Systems. Learn More
    $37.99 Special Price $26.99 As low as $22.99
  15. HYDROTECH S-FS-17 - 9 GPD TFC RO Reverse Osmosis Membrane #4140003, 33001071- 1000
    Hydrotech ® S-FS-17 9 GPD TFC RO Reverse Osmosis Membrane # 41400003, 33001071 (#41400004)
    Hydrotech ® S-FS-17 9 GPD Reverse Osmsosis RO Membrane Has Been Discontinued And Is No Longer Available. If You Order The S-SF-17 9 GPD TFC Membrane You Will Receive The Hydrotech S-FS-07 15 GPD TFC Membrane #41400004. #41400003 (Green/Red Band) #33001071 (Yellow/Red Band or Blue/Red Band) For HT & HTF Series Reverse Osmosis RO Systems. Learn More
    $99.99 Special Price $69.99 As low as $54.99
  16. Hydrotech ® S-FS-19 & Aquafier Carbon Block Replacement Water Filter # 41400009
    Hydrotech ® S-FS-19 & Aquafier Carbon Block Water Filter # 41400009
    Hydrotech ® S-FS-19 & Aquafier Carbon Block Water Filter. CTO 10 Micron (Blue End Caps) # 41400009 For HT & HTF Series Reverse Osmosis RO Systems. a.k.a. #41400075 Learn More
    $21.99 Special Price $12.99 As low as $9.99
  17. Hydrotech S-FS-20 45 GPD TFC RO Reverse Osmosis Membrane #41400007 - 1000
    Hydrotech ® S-FS-20 45 GPD TFC RO Reverse Osmosis Membrane # 41400007/33001033
    Hydrotech ® S-FS-20 45 GPD TFC Reverse Osmosis RO Membrane. (Green/Orange Band) # 41400007 For HT & HTF Series Reverse Osmosis RO Systems. The #41400007 has been replaced with the 50 GPD #33001033. If you order the #41400007 you will receive the #33001033. Learn More
    $139.99 Special Price $99.99 As low as $79.99
  18. Hydrotech ® S-FS-24 & Aquafier Carbon Block Replacement Water Filter # 41400011
    Hydrotech ® S-FS-24 & Aquafier Carbon Block Replacement Water Filter # 41400011
    Hydrotech ® S-FS-24 & Aquafier 5 Micron Carbon Block Water Filter with Coconut. (White End Caps) # 41400011 For Aquafier Series Reverse Osmosis RO Systems. Learn More
    $29.99 Special Price $18.99 As low as $16.49
  19. Hydrotech ® HT-HTF & Aquafier Filter Housing Sump # 20500023
    Hydrotech ® HT-HTF & Aquafier Filter Housing Sump # 20500023
    Hydrotech ® HT-HTF & Aquafier Replacement Water Filter Housing Sump. # C-HT-19 # 20500023 For HT-HTF and Aquafier Series Reverse Osmosis RO Systems. Learn More
    $39.99 Special Price $27.99 As low as $24.99
  20. HYDROTECH 50 GPD TFC RO Reverse Osmosis Membrane #33001033- 1000
    Hydrotech ® 50 GPD TFC RO Membrane #33001033
    Hydrotech ® 3300103 50 GPD TFC Reverse Osmosis RO Membrane. (Yellow/White Band or Blue/White Band) # 33001033 For HT & HTF Series Reverse Osmosis RO Systems. Learn More
    $139.99 Special Price $99.99 As low as $79.99
  21. Hydrotech ® 34201026, Hydrofiner & Aquafier O-ring for water filter housing sump
    Hydrotech ® 34201026 & Aquafier O-ring for filter housing
    Hydrotech ® 34201026 & Aquafier O-ring for filter housing. Fits Hydrotech, Aquafier and Hydrofiner systems. 2 1/2" diameter Learn More
    $8.99 Special Price $4.99 As low as $3.39
  22.  Inversion Tank Stand Reverse Osmosis System
    Inversion Tank Stand Reverse Osmosis System
    Protect the bladder of your tank by using our tank inversion stand. Most tanks hold the water in the top portion of the tank instead of the bottom. Storing the water on top of the bladder adds the weight of the water to the pressure to cause unnecessary stress on the bladder. By inverting (turning upside down) it removes the weight of the water on the seal where the bladder is attached to the inside of the tank. Fits most standard 3 and 4 gallon tanks. Plastic Inversion RO Tank Stand. UPC #850901003408 Learn More
    $27.99 Special Price $17.99
  23. GGN-Faucet-AG-P-Chrome Air Gap Faucet-Long Reach-1000
    $39.99 Special Price $29.99
  24. 4 Gallon Reverse Osmosis Tank GGN-Tank-4-Pro-3.2
    4 Gallon Reverse Osmosis Tank GGN-Tank-4-Pro-3.2
    GGN-Tank-4 - 4 Gallon RO Reverse Osmosis Tank 1/4" NPT Threads. Stainless Steel connector. This is the perfect replacement tank for most residential RO Reverse Osmosis systems. Set Air Pre Charge To 7 psi With The Tank Empty Blue color. UPC #850901003491 Learn More
    $79.99 Special Price $49.99

Easy TDS Membrane Performence Calculator
See If It is Time To Replace Your Membrane

Simply enter your Feed Water TDS and RO Water TDS into the boxes above and click "Submit". The percentage of TDS Rejection will be displayed. We normally recommend membrane replacement once you drop below 75%. This may vary in areas with high TDS in the feed water.

See our selection of TDS meters under Water Tests


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.


* Arrowhead ® is the registered trademark of Arrowhead, the manufacturer of Arrowhead ® brand water treatment equipment.  The replacement filters and membranes listed above are not manufactured or endorsed by Arrowhead.  Rather, these filters and membranes are manufactured by other companies.  While these filters and membranes are compatible for use in Arrowhead ® brand water treatment equipment, we make no representation as to whether using these filters and membranes is consistent with the warranty and specifications applicable to Arrowhead ® equipment.