Bulk Reef Supply

4 Stage Value Plus 75GPD RO/DI System

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BRS 4 Stage Systems are perfect for reefers who have water treated with chlorine or relatively clean well water. The 4 stage systems are self-contained on a single bracket making them ideal for tight spaces or where a non-permanent connection may be required. Installing a RO/DI system only takes a few minutes and can be done very easily without any permanent modifications to your home or the plumbing.

4 Stage Plus RO/DI Features:

  • Dual TDS Meter
  • Glycerin Filled Pressure Gauge
  • Pre-installed Automatic shut-off valve
  • Pre-installed Flush Kit
  • Multiple source water connections
  • Drain/waste water connections
  • Mur-lok Push Connect dual EPDM O-Ring fittings
  • 10 Ft Each of 1/4" Blue, Red and Black Tubing
  • Pre-installed NSF Certified Filters NSF Certified


Lifetime Warranty All Bulk Reef Supply RO/DI Systems are covered by our Limited Lifetime Warranty.


Bulk Reef Supply RO/DI systems only use the latest filters and components in Reverse Osmosis technology. We have designed our RO/DI units especially for reef tanks, but they can produce perfect water for other types of saltwater and freshwater aquariums too. If you have a well, or you are connected to city water we provide a variety of RO/DI systems that will fit your aquarium's needs.


4 Stage RO/DI Systems - Perfect for city water that is treated with low amounts of chlorine, or well water with very minimal contaminants.
5 Stage RO/DI Systems - Our most popular system handles most types of well water along with most types of city water treated with chlorine including small amounts of chloramines.
6 Stage RO/DI Systems - If you are not sure what is in your water, or it contains excessive amounts of TDS or hard to remove contaminants like chloramines, phosphates, nitrates, silicates, etc. The BRS 6 Stage systems are designed to treat any water your home may have effectively. The Dual DI stage helps with the hard to remove ions like ammonia, phosphates, silicates, etc.


4 Stages of Filtration

Stage 1

Purtrex 5 Micron Depth Sediment Filter NSF Certified

Sediment filters trap debris and other free-floating particles that would normally clog expensive carbon blocks and foul membranes. Purtrex filters are an actual depth filter with a graded density that progressively gets tighter through as water passes through the filter allowing them to last longer than the competitors.

Stage 2

BRS 5 Micron VOC Block NSF Certified (Chlorine 15,000 @ 1 GPM)

Our VOC carbon blocks are specially formulated to remove and reduce chlorine and volatile organic compounds from household water.

Stage 3

75 GPD Dow Filmtec Membrane NSF Certified (up to 99% rejection rate*)

DOW is hands down the industry leader for residential RO membranes. The 75 GPD Filmtec membrane can remove up to 99% of contaminants from traditional household drinking water. All membranes do require pressure to operate correctly, and DOW's membrane only requires 50 PSI of feed pressure to operate efficiently.
For more info on DOW membranes - Click Here

Stage 4

Nuclear Grade Color-Changing Deionization Resin

Deionization resin is the final stage of the RODI system and can polish your water down to 0 TDS. The DI resin is a mixed bed with a color changing indicator to let you know when it is becoming depleted. The resin starts as a dark blue color that will turn gold when as it becomes exhausted and is a good indicator to let you know when to start looking at your TDS meter.
For more info on Color Changing DI Resin - Click Here


Need Replacement Filters? 4 Stage Chlorine/VOC Filter Kit


BRS RO/DI 4 Stage System Comparison

  BRS 4 Value RO/DI Systems BRS 4 Value Plus RO/DI Systems
Gallons Per Day
75, 100, 150, or 200
75, 100, 150, or 200
Sediment Filter
Purtrex 5 Micron Depth Sediment Filter 
Purtrex 5 Micron Depth Sediment Filter 
Carbon Block
BRS VOC 5 Micron Carbon Block 
BRS VOC 5 Micron Carbon Block  
75 or 100 GPD Dow Filmtec Membrane

75 or 100 GPD Dow Filmtec Membrane

Single Mixed Bed DI Stage with Refillable Cartridge

Single Mixed Bed DI Stage with Refillable Cartridge

Auto Shut Off Valve
Canister Wrench
Laundry Tub Connection Adapter
Chrome Faucet Diverter Valve
Glycerin Filled Pressure Gauge  

Flush Kit  
Dual Inline TDS Meter  
Dimensions 16" x 6.25" x 15.5" 16" x 7" x 15.5"


4 Stage Plus RO/DI System Recommended Conditions:

  • Minimum Water Pressure - 50 PSI
  • Max Water Pressure - 90 PSI
  • Recommended Water Temperature - 77°F
  • Recommended Max TDS - <300ppm

Water pressure can be increased by adding a booster pump before your RO/DI system if a pressure increase is required. Low pressure will cause slow production of product water, with excess production of waste water. Pressure over 90 PSI may cause damage to the RO/DI units filters and components.


*DOW Filmtec 75 GPD Membranes have a 96% - 99% typical stabilized salt rejection rate that can be reproduced through the following conditions;

  • Source Water Pressure - 50 PSI / Membrane
  • Source Water Temperature - 77°F
  • Source Water TDS - 250ppm Softened Tap Water
  • Recovery - 15%
  • Minimum Salt Rejection - 96%

For more info on DOW Filmtec BW60-1812-75 Membrane - Click Here


BRS 4 Stage Plus RO/DI Owners Manual

Dow Filmtec Membrane BW60-1812-75

More Information
UPC 853710007742

BRS 4 Stage Plus RO/DI Owners Manual

Dow Filmtec Membrane BW60-1812-75

Stages 4 Stage
Production Rate 75 Gallons per Day
Waste:Product Water Standard (3:1)
Dimensions 16" x 7" x 15.5"
Filter Dimensions 10 in. x 2.5 in. (Standard)
Tubing Length 10 Ft Each of 1/4" Blue, Red and Black Tubing
Included Filters Sediment Filter, Carbon Block, RO Membrane, DI Resin (Mixed Bed)
Included Accessories Flush Kit, Pressure Gauge, TDS Meter, Faucet & Garden Hose Connections
Warranty BRS Limited Lifetime Warranty
TDS Meter Type Dual
Carbon Block Type Chlorine
Sediment Filter Type True Gradient Technology
Membrane GPD 75
Micron Rating 5
Resin Type Color Changing
Water Supply Connections Faucet Diverter Valves, Garden Hose / Laundry Tub
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Product Questions

I just replaced all the filtration media and the middle canister (carbon block) is leaking at a slow drip rate. It didn't leak before I took it off. Took it apart again and the O-ring looks secure and it's still leaking. I can't tighten it any further. Do you have any tips I can try to stop it? Is it OK to use Teflon tape on the threads?
Question by: Betsy on Apr 20, 2023, 2:06 PM
I would try replacement of the o-ring. I am guessing it got a small pinch in it somewhere. Here is a link below. Rather cheap part to start. Unlikely the canister has an issue but if it does we sell it and its sku# 200001
Answer by: Tyler Schafer (BRS Staff) on Apr 21, 2023, 12:41 PM
I have a water softener how does this affect the R/O system
Question by: Chu-e on Dec 19, 2022, 5:27 PM
Thanks for reaching out to us! The water softener will help remove some calcium, magnesium, and other hardness causing elements that will make the filters last longer for the RODI unit. Let us know if we can help with anything else!
Answer by: Kyle Thomas (BRS Staff) on Dec 20, 2022, 3:31 PM
Does this system come with the filtration media? Also, what is the waste to pure water ratio. How much water am I wasting to make one gallon of RODI water?
Question by: Shane on Jun 5, 2022, 5:05 PM
Thanks for the questions! All of our RODI units come with the first filters, membranes, and DI resin installed. This particular system with the right water pressure (65-70 PSI) and average TDS initially, should have a 3:1 ratio of waste to product (ie for every 1 gallon of water made, 3 gallons will be waste).
Answer by: Kyle Thomas (BRS Staff) on Jun 7, 2022, 11:19 AM
Can this system be upgradable to a 7 stage?
Question by: Yang on Feb 15, 2022, 5:43 AM
Hey there,Thank you for reaching out to us.

This unit can be upgraded to a 7-stage. You can see how at the video below.
Answer by: Matt Lucero (BRS Staff) on Feb 15, 2022, 7:35 AM
Can this system be upgrade to a 7 stage system ?
Question by: Kevin on Feb 15, 2022, 5:10 AM
Hey there,
Thank you for reaching out to us.
Yes, it can be upgraded to a 7-stage. It can be seen at the video below.

Answer by: Matt Lucero (BRS Staff) on Feb 15, 2022, 7:34 AM
How do you flush the system. I assume flush valve is open during normal operation.
Question by: Paul Blasi on Dec 15, 2021, 11:22 AM
Thank you for your question. To flush the system you open the flush valve so that the handle is parallel to the flush valve and let the system run for 5-10 minutes. When it is closed (in the perpendicular position) the flow restrictor is engaged and the system will produce filtered water.
Answer by: William Glenn (BRS Staff) on Dec 16, 2021, 1:38 PM
Where is the DI resin placed in this? it says 4 stage and i don't believe that is the resin area.
Question by: steve on Mar 13, 2018, 10:28 PM
Hi there,
Thank you for reaching out.
In the 4 stage system the filtration goes like this:
Sediment filter -> Carbon Block -> RO Membrane -> DI Resin
The DI resin is located in the 3rd canister on the bottom of the bracket.
Please let us know if you have any other questions.
Have a great day!
Answer by: William Glenn on Mar 16, 2018, 2:22 PM
Does this unit come with the float valve or do i buy it separately?
Question by: Alex Cheshmejiev on May 21, 2017, 11:38 AM
Hey there,
The 4 Stage Value and Plus unit do not include the float valve, so this would need to be purchased separately.

Have a great day!
Answer by: Zack on May 23, 2017, 3:17 PM
A few things. Just got this up and running, the unit is making a hissing type sound but not leaking. I can't tell what way is off for the flush kit ball valve (what way I should have it when running) cause when it is inline it doesn't make a sound but when it is perpendicular it has a 40psi pressure (double inline).
Question by: Sean Fennig on May 2, 2017, 5:56 PM
Hey there,
It's not unusual to hear a bit of noise through the unit when it's got water running through it, but this can be much more noticeable when the unit is first started as this comes from little bits of air trapped in the unit. As the unit wears in, much of these air bubbles will get purged from the system and the noise will quiet down. If you are getting a lot of noise initially, moving the unit around a bit, even laying it on its side and tapping it can help to release some of this air and allow it to pass through the system. If you have further questions about your system, please feel free to contact our free customer support by phone or email.

Customer Service- 763-432-9691. Email support@bulkreefsupply.com

Hope this helps!
Answer by: Zack on May 8, 2017, 11:12 AM