Expert Advice on Selecting a RODI System

How to Choose a RODI (reverse osmosis deionization) System

On this page, we go over everything you need to know to select which RODI system is best for you. If any of the terms are unfamiliar to you, please check the definitions section at the bottom of this page.

 

Table of Contents

 

What is a RODI System?

A RODI system combines reverse osmosis and deionization to remove impurities from water. The process involves multiple stages:

  • Sediment Filters: Removes larger particles like sand and silt.
  • Carbon Filters: Eliminates chlorine and organic compounds.
  • Reverse Osmosis Membranes: Removes up to 99% of dissolved solids.
  • Deionization Resins: Removes remaining ions to get ZERO TDS.

 

Why buy a RODI System from Air, Water & Ice ?

Our RODI systems are designed so you may begin making zero TDS water immediately. You only need to connect your tap water and drain water and you are done, then enjoy zero TDS water, Zip, Zero, Zilch, Nada. NO TDS. 40 years and tens of thousands of reefkeepers later and still no reports of problems. We offer you a complete one frame system which has all the protection you will ever need. All of our RODI systems are made in the USA in our warehouse in Georgia using the highest rated filters and parts we can find across the globe. Our RODI systems come to you fully assembled and are 100% plug and play. We build, test and heavy duty pack your RODI system from scratch in house. We offer many system options directly on the product pages so you can get the exact system you need. All of our RODI systems include a first class installation hardware kit, easy to understand instructions and a hassle free automatic filter change reminder with a coupon! People love us and tell their friends because we ALWAYS put customer service as our #1 priority, if you need any assistance, guidance or have any questions, please do not hesitate to contact one of our friendly water experts today! 772-461-0256 / sales@airwaterice.com

We are committed to quality. We install heavy duty Pre-filters in our RODI systems. Our prefilters are often twice as heavy as the cheapo lightweight filters you see all over the internet and found in big box stores. Our 98-99% rejection rate RO membranes we install fresh the day you order in your system are factory direct and lubricated with molykote to make changing the membrane easy - they are not the cheap 95%-97% rejection rate membranes found elsewhere. Our nuclear grade di resin from resintech is the same resin used in US nuclear submarines. We professionally pack your refillable di cartridge the day you order to ensure freshness. 

 

Who uses Air, Water & Ice's RODI Systems?

Coral reef keepers are very demanding and require reliable and specialized RODI units that have been specifically designed to fit their needs. All of our RODI (Reverse Osmosis Deionization) systems are perfect for:

  • ZERO TDS water for saltwater coral reef aquariums,
  • laboratories,
  • semiconductor cleaning,
  • car detailing,
  • industrial cleaning,
  • dental office instrument cleaning,
  • many other ultra pure water applications

We market all over the world. In the United States we provide water purification solutions to over 200 reef clubs, over 250 local fish stores (LFS), over 50 well known university biology labs and several other specialized industries. Some of our more well known clients include Coca~Cola, Harvard University, Nelson -Atkins Museum of Art and the Metropolitan Museum of Art in New York. 

 

Differences Between our RODI Systems

We are currently offering eleven different RODI units. The TYPHOON series is our most popular series of reefkeeping RODI units. We have now built and sold over 20,000 Typhoon units through October 2025 and every one is still under our lifetime replacement parts warranty. Our Typhoon Reefkeeper RODI's can be used on ANY city tap water or well water. Depending upon which membrane you select on the product page, this unit can be configured to deliver between 50 and 150 gallons of pure RODI water a day. That's 2 to 6 gallons per hour! For the Typhoon series RODI's, we offer a good, better and best model. Below is a brief product overview of each one :

TYPHOON 5 STAGE REEFKEEPER RODI

Our Typhoon RODI system has everything you need to make RODI water immediately. It is equipped with an asov for automatic top-off. This RODI system is designed to easily add on accessories in the future. This system is excellent for good to poor* city or well water quality. Poor water quality clogs filters. When you have THREE heavy duty pre-filter stages you ALWAYS get better results than systems with only TWO prefilters. Configure this system with a 50 - 150 GPD or dual 75 GPD membrane(s) right on the product page.

*poor water quality is defined as greater than 300 to 1100 ppm tds OR hard water OR water with strong odors OR water with any discoloration.

Typhoon Series' 5 stages of filtration Equals LESS filter changes & MORE pure water.

✔ STAGE 1 : Heavy Duty standard industry size Poly Pro 10 Micron Sediment filter

✔ STAGE 2 : Acid washed CTO/GEM coconut shell activated 5 Micron Carbon Block filter, removes 98-99% of chlorine OR upgrade to Catalytic Carbon*

✔ STAGE 3 : Acid washed CTO/GEM coconut shell activated 1 Micron Carbon Block filter, removes the remaining chemicals and chlorine.

✔ STAGE 4 : Select a 50, 75, 100 or 150 or dual 75 gallon per day (GPD) RO membrane(s) with the best 98-99% rejection rates in the industry. (note! Our 50 GPD makes about 2 gallons of RODI water per hour, Our 150 GPD makes about 6 gallons per hour)

✔ STAGE 5 : A professionally packed full 10" Nuclear Grade Color Changing Refillable DI Resin Cartridge to get down to ZEO TDS. We buy our resin in bulk direct from Resintech and we guarantee OUR di resins to be of the highest quality available with a very apparent color change as the resin exhausts from a blue to a light gold/amber color

*The Water Quality Association recommends Catalytic Carbon as a prefilter for POU (point of use) if you are on well water or if your city uses chloramines to disinfect the water. Not sure? Call or text us 772-461-0256 and we can immediately look up your water quality report. Our catalytic carbon filter removes more than 5 times the chloramines of any carbon block - even the ones that are specially designed to "guard" or "bust" chloramines. 

Our Typhoon RODI system series is a great option for up to 300 Gallons of RODI / ultrapure water a month.

 

TYPHOON III 5 STAGE REEFKEEPER RODI

TYPHOON III 5 STAGE REEFKEEPER RODI

Our Typhoon III RODI system features our money saving DI bypass assembly. Configure this system with a 100 or 150 GPD membrane right on the product page. This RODI system includes everything from our Typhoon RODI system PLUS:

 


TYPHOON III EXTREME 5 STAGE REEFKEEPER RODI

Our Typhoon III Extreme RODI system is a highly advanced version of all of our Typhoon RODI systems. Perfect for the novice or professional, this RODI system is designed as a one stop-complete package for a new saltwater tank build or restart. This RODI system includes everything from our Typhoon III RODI system PLUS:

 


COMPACT 5 STAGE REEFKEEPER RODI

Our Compact RODI system features the same THREE heavy duty prefilter stages as our Typhoon series RODI systems. The main difference is the final DI stage is a clear refillable inline DI filter that clips on top of the system's membrane housing instead of a full 10" DI resin cartridge. Configure this system with a 50 - 100 GPD membrane right on the product page. This RODI system is ideal for users with limited space or have better than average tap water quality (less than 250 ppm tds).

Our Compact RODI system series is a great option for up to 100 Gallons of RODI / ultrapure water a month.

 


COMPACT III 5 STAGE REEFKEEPER RODI

Our Compact III RODI system features our money saving DI bypass assembly. This RODI system includes everything from our Compact RODI system PLUS:

 


CYCLONE 4 STAGE REEFKEEPER RODI

Our Cyclone RODI system features TWO prefilter stages: a Heavy Duty standard industry size Poly Pro Five Micron Sediment filter and a Acid Washed CTO/GEM coconut shell activated One Micron Carbon Block filter. This RODI system also features the same professionally packed full 10" Nuclear Grade Color Changing Refillable DI Resin Cartridge to get down to ZEO TDS from ResinTech as our Typhoon series RODI systems. This space saving design is ideal for users with city water treated with chlorine and not chloramines to disinfect the water. Contact us if you are not sure and we can look up your water quality report immediately. 772-461-0256 or sales@airwaterice.com. Configure this system with a 50-150 GPD membrane, even a dual 75GPD membrane right on the product page. 

Our Cyclone RODI system is a great option for up to 100 Gallons of RODI / ultrapure water a month.



MIGHTY MITE WITH DI 4 STAGE REEFKEEPER RODI

Our Mighty Mite with DI RODI system is our budget friendly complete RODI reef water system that is specially designed for aquarium enthusiasts who have a nano tank or 50-gallon tank or smaller. It's the perfect solution for those living in smaller homes or apartments who don't want to compromise on quality when it comes to a RODI system. The Mighty Mite DI RODI system features a four-stage filtration process: an inline sediment filter, an inline carbon filter, a 50 GPD membrane, and a refillable clear inline DI filter. This system is perfect for the beginner, those who need very little RODI ultrapure water or would like to have an emergency RODI system backup.

Our Mighty Mite RODI system is a great option for up to 50 Gallons of RODI / ultrapure water a month.

 


NEPTUNE 8 STAGE 200 GPD REEFKEEPER RODI

Our Neptune RODI system is designed to provide Reefkeepers and laboratories with ultra-pure water, free of ammonia and silicates, delivering -0- TDS. It is a full-scale, high-production water purification system capable of producing the necessary water to sustain very large or numerous aquatic systems. It is also ideal for semiconductor cleaning operations or labs requiring large quantities of ultra-clean zero TDS water. Used at Harvard University and many other college biological science laboratories-if you need a lot of ultrapure water, you have found the right system. 

Neptune 8 stages of filtration Equals LESS filter changes & MORE pure water.

✔ STAGE 1 : Heavy Duty standard industry size Poly Pro 10 Micron Sediment filter

✔ STAGE 2 : Acid washed CTO/GEM coconut shell activated 5 Micron Carbon Block filter, removes 98-99% of chlorine OR upgrade to Catalytic Carbon*

✔ STAGE 3 : Acid washed CTO/GEM coconut shell activated 1 Micron Carbon Block filter, removes the remaining chemicals and chlorine.

✔ STAGE 4-5 : 2 x 100 GPD Filmtec RO membranes with the best 98% rejection rates in the industry.

✔ STAGE 6-8 : Option 1: 3 x professionally packed full 10" Nuclear Grade Color Changing Refillable Mixed Bed DI Resin Cartridges OR Option 2: 1 x Cation, 1 Anion and 1 x Mixed Bed DI Resin Cartridge, to get down to ZEO TDS. We buy our resin in bulk direct from Resintech and we guarantee OUR di resins to be of the highest quality available with a very apparent color change as the resin exhausts from a blue or purple to a light gold/amber color. 

*The Water Quality Association recommends Catalytic Carbon as a prefilter for POU (point of use) if you are on well water or if your city uses chloramines to disinfect the water. Not sure? Call or text us 772-461-0256 and we can immediately look up your water quality report. Our catalytic carbon filter removes more than 5 times the chloramines of any carbon block - even the ones that are specially designed to "guard" or "bust" chloramines. 

Our Neptune RODI system is a great option for up to 750 Gallons of RODI / ultrapure water a month.

 


DUAL HOME REEF 6 STAGE REEFKEEPER RODI

Our Dual Home Reef RODI system is our COMPACT 5 STAGE REEFKEEPER RODI system from above with our add drinking water kit preinstalled. Select from a 3-20 gallon NSF RO Pressure Tank and 5 different RO faucets. This RODI system is configured with a 50 GPD FilmTec membrane. This model is specifically designed to provide absolutely pure, lab-grade RO/DI water for your reef, while also supplying you with a constant flow of exceptionally purified RO drinking water. This is also our most customized system. Contact us to add a permeate pump or larger GPD membrane size at no additional installation charge beyond the price of the products. 772-461-0256 or sales@airwaterice.com. We recommend this system if your are going to use more RO drinking water than RODI water. If you plan on using more RODI water than RO drinking water, we recommend our Hurricane Dual Home Reef.

Our Dual Home Reef RODI system is a great option for up to 100 Gallons of RODI / ultrapure water a month.

 


HURRICANE DUAL HOME REEF 5 STAGE REEFKEEPER RODI

Our Hurricane Dual Home Reef RODI system is one of a kind chloramine guzzling pure water machine. A non-electric permeate pump is pre-installed to dramatically boost your pure RO water flow rate, pressure, water purity and cut your drain water in half at the same time. Select a 50, 75 or 100 GPD membrane, a 3-20 gallon NSF RO Pressure Tank and chose one of 5 different RO faucets. This model is specifically designed to provide absolutely pure, lab-grade RO/DI water for your reef, while also supplying you with a constant pressure boosted flow of exceptionally purified RO drinking water. We recommend this system if your are going to use more RODI drinking water than RO drinking water. If you plan on using more RO drinking water than RODI water, we recommend our Dual Home Reef.

Hurricane 5 stages of filtration Equals LESS filter changes & MORE pure water.

✔ STAGE 1 : Poly Pro 5 Micron Inline Sediment filter

✔ STAGE 2 :  Professionally packed 10" Catalytic Carbon Cartridge

✔ STAGE 3 :  Select a 50, 75, or 100 gallon per day (GPD) RO membrane with the best 98-99% rejection rates in the industry. (note! Our 50 GPD makes about 2 gallons of RODI water per hour, Our 100 GPD makes about 4 gallons per hour)

✔ STAGE 4 (Drinking RO Water side): Acid washed CTO/GEM coconut shell activated Inline Carbon filter, removes the remaining chemicals and chlorine.

✔ STAGE 5 (RODI Water side): A professionally packed Nuclear Grade Color Changing Refillable Inline DI Resin Cartridge to get down to ZEO TDS. We buy our resin in bulk direct from Resintech and we guarantee OUR DI resins to be of the highest quality available with a very apparent color change as the resin exhausts from a blue to a light gold/amber color

Our Hurricane Dual Home Reef RODI system is a great option for up to 200 Gallons of RODI / ultrapure water a month.

 


1000 GPD PUMP DRIVEN COMMERCIAL 12 STAGE REEFKEEPER RODI


Our 1000 GPD Pump Driven Commercial RODI system is specifically designed for local fish stores (LFS) and small businesses to provide a sustainable low cost solution to making ultrapure RODI water without ammonia or silicates. After 40+ years of watching prices soar for the merlin and hydrologic parts and membranes, we knew we you needed something that will never leave you without pure RODI water. This system is designed like how a tree uses its roots to pull water. What EVERY business owner wants is a non-hassle system that is affordable and easy to manage (i.e. ability to train someone else to do it). THIS is the system for you. This system has been made for over 25 years and we always have ALL the parts and filters for this system. This specific system was designed to make ultrapure water in the most affordable way with the industries highest rejection rated products. That is exactly what this system is. Instead of paying for a low 92-95% rejection rate system (evolution/merlin), this system has a 96-98% Rejection Rate in most applications and with a 1.7 GPM (gallon per minute) aquatec pump, you are guaranteed production rates that far exceed any system without a pump. For example, this system maxed out with 6 x 150 GPD membranes and the 1.7 GPM pump makes about DOUBLE the production of RO water compared to the "ge/merlin/hydrologic/hawthorne EVOLUTION RO 1000 in most of our new installations. Ideal for those who need a lot of RODI water. See a video of this system in action with 60 degree cold water here.

1000 GPD Pump Driven Commercial's 12 stages of filtration Equals LESS filter changes & MORE pure water.

✔ STAGE 1 : 20" Heavy Duty Poly Pro 10 Micron Sediment filter

✔ STAGE 2 : 1.7 GPM (gallon per minute) Aquatec Booster Pump.

✔ STAGE 3 : 20" Acid washed CTO/GEM coconut shell activated 5 Micron Carbon Block filter, removes 98-99% of chlorine OR upgrade to Catalytic Carbon*

✔ STAGE 4 : 20" Acid washed CTO/GEM coconut shell activated 5 Micron Carbon Block filter, removes the remaining chemicals and chlorine.

✔ STAGE 5-10 : 6 x 150 GPD Axeon RO membranes with the best 98% rejection rates in the industry.

✔ STAGE 11-12 : Twin DI with Inline TDS meter (option) consist of a dual TDS meter and TWO professionally packed full 20" Nuclear Grade Color Changing Refillable Mixed Bed DI Resin Cartridges to get down to ZEO TDS. We buy our resin in bulk direct from Resintech and we guarantee OUR di resins to be of the highest quality available with a very apparent color change as the resin exhausts from a blue or purple to a light gold/amber color. 

Our 1000 GPD Pump Driven Commercial RODI system is a great option for 1,000-6,000 Gallons of RODI / ultrapure water a month.

 

How Long do Filters Last? Filter Life and Replacement Schedule

Prefilters (Stages 1-3): All of our systems have 2 or 3 prefilters. Prefilters are usually sediment and carbon filters. Prefilters protect your RO membrane, remove sediment, particles, organic chemicals, chlorine and chloramines (if upgraded to catalytic carbon). Sediment and Carbon prefilters should be replaced at least annually OR every 3,000 total gallons (whichever comes first). 3,000 total gallons means they will provide at least 750 gallons of pure RO water (about TWO gallons per day for ONE year before needing to be replaced). Inline filters provide HALF this amount. 

RO Membrane Stage: All of our systems have a membrane installed in the horizontal tube with the cap found on the top of our RO systems. The membrane is the heart of the system doing most of the work, removing 98-99% of TDS (total dissolved solids). Our membranes are rated to process between 6,000-15,000 total gallons, typically every 2-5 years. Replace prefilters on time and your membrane will last longer! Specifically we replace membranes when they get clogged or no longer produce at least a 90% rejection rate. You can easily find your membranes rejection rate with a TDS meter. Please see our FAQ on how to easily perform a tds test and know your membranes rejection rate. 

DI Resin Final Stage: All RODI systems have a final polishing filter to remove the remaining TDS not filtered out by the membrane. The DI resin removes any remaining TDS left by the FilmTec or Axeon membrane(s), providing ZERO TDS water. Our nuclear grade color changing deionization resin is professionally packed in a refillable 10" or inline DI cartridge and installed in your system the day your order ships. As the DI resin is used, the color changes from a blue/purple to a light golden brown color. Once the color change is complete, you simply install a new di cartridge or buy our bulk resin and refill it. Our deionization nuclear grade resin is a mixed bed of 50% Anion & 50% Cation resins made by ResinTech. Our 10" di resin cartridge can hold a minimum of 3,000 ppm tds (capacity) before the di resin's color change is over 50% and you will no longer get zero TDS. How to estimate DI resin life? Let's do a quick example: If your pure RO water is 10 ppm tds, you should get at least 300 zero tds gallons [300 gallons= 3,000 ppm (minimum di resin capacity) divided by 10 ppm (your RO water quality) ]. If your pure RO water quality is 5 ppm you would get at least 600 zero tds gallons [600=3,000 divided by 5]. Our inline DI cartridge holds HALF this amount. Replace prefilters and membrane(s) on time and your Membrane and DI resin stage will last much longer. 

***All of our systems and filter packs purchased on our website include a automatic hassle-free FILTER CHANGE REMINDER WITH A COUPON exactly 11 months after you make your purchase. No signup's needed. No need for a credit card on file. No cancellations = we make it easy for you. Please save our email sales@airwaterice.com to your email contacts!

 

Definitions and Terms for RODI Systems

ASOV: (automatic shut off valve) A hydraulic valve that is connected to the system and automatically stops the flow of feed water when the system is closed. Add a float valve and you make water automatically.

Stages: The number of filters that make up the total system. We use a step down method array of filters that has proven over time to provide better results in every application. To truly understand which micron rating to use where, please visit our Filter Array Recommendation page for more information.

GPD: (gallons per day) The GPD is a RO membrane rating that is based on a water temperature of 77 degrees and water pressure of 50 PSI (60 psi for 150GPD). The most common confusion is someone says "I don't use 50 gallons per day"... think of the GPD rating in terms of the SPEED of the RO water produced... (a 50 GPD membrane makes only TWO gallons of RO water in ONE hour, a 150 GPD makes ONE gallon every TEN minutes). RO membranes remove 90% to 99% of the feed water TDS. 

TDS: (total dissolved solids) The world measures water quality in PPM (parts per million) TDS.  In the USA, the average tap water is 250 ppm tds out of your sink faucet. We consistently get everyone under 10 ppm tds for the pure RO water. The di resin should always be 0 ppm tds. TDS testing is as simple as pressing a button on a tds meter and you immediately get your ppm tds number. Click here to see our FAQ on how to perform a tds test.  

TDS Creep: Water is a solvent. Water that is allowed to sit inside a RODI system gains TDS. This TDS is primarily carbon dioxide from the air. To remove TDS creep get a system with a DI bypass or purchase our DI bypass accessory separately and send this higher TDS creep water directly down the drain and extend the life of your membrane and DI resin cartridge. 

TDS Meter: A TDS meter is a great way to instantly know your water quality. The world measures water quality in PPM (parts per million) TDS (total dissolved solids).  In the USA, the average tap water is 250 ppm tds out of your faucet. We consistently get everyone under 10 ppm tds for the pure RO water. The RODI water after the di resin should always be 0 ppm tds. TDS testing is as simple as pressing a button and you immediately get your ppm tds number. Click here to see our FAQ on how to perform a tds test.  

DI Resin or Deionization: This is almost always the final stage used for reducing the membrane's pure RO water output TDS to zero.

Microbiologically Safe: If you are under a "boil watch" do not use any RODI system. No RODI system that has every been designed should be used if the water is not microbiologically sound. 

Clear Filter Housings: Allow you to see your filters.

PSI Gauge: Measures line pressure, useful to identify clogged filters or membranes or to fine tune a booster pump.

Fast Flush Flow Restrictor: Mechanism connected to the waste water line of the system which allows flushing of the membrane to prolong its life. This flushing removes the stale water in the unit to eliminate TDS creep.

Waste to Pure Water Ratio / Recovery Rate: Most of our systems get a 3:1 waste to pure water ratio. That's a 25% recovery rate. Your RO membrane wants a 15% recovery rate to get its stated rejection rate (98-99%) and lifespan. We do sell "water saver" add on membrane kits that will allow you to achieve closer to a 2:1 and even a 1:1 waste to pure water ratio. We don't suggest this for most RODI users as you WILL get lower rejection (1-2%) rates from your membranes and you WILL spend more money on DI resin. Unless you have a relatively clean well, have over 60 psi water and are also concerned that you might fill up your sump, we don't suggest adding a second membrane to conserve water (plumb membranes in series) for ANY of our RODI users. Adding a membrane parallel (see diagram) is a different story and is typically used with a booster pump.

DI Bypass Valve: The bypass extends the life of your membrane and DI resin cartridge. The DI bypass allows you to flush your pure RO water line, membrane and prefilters and send the stale "tds creep" water directly down the drain which greatly extends the life of your membrane and di resin. If you have poor tap water quality, we highly recommend a di bypass as this will greatly prolong the life of your filters. The auxiliary RO port is great for several reasons. 

RO Only Valve: Allows you to get water out of unit after the membrane but before the DI filter. All systems with a DI bypass have this feature. This auxiliary RO port is often used for evaporation top off in certain situations, watering plants or as a drinking water valve. 

Installation Hardware Kit: All of our RODI systems include a first class installation hardware kit that includes: 24 feet of standard NSF 1/4" Tubing, a drain saddle, 2 x inline ball valves, a filter housing wrench and a tap water supply connection of your choice, 

 

Contact Us for Questions on Selecting a RODI System!

If you have further questions on which RODI system will be the best RODI system for you, please reach out to one of our friendly water experts via phone at (772) 461-0256 or by email at sales@airwaterice.com. We can help answer any questions about which RODI system you should choose, look up your water quality report, compare RODI systems, installing your system, maintaining your system, and more. At Air, Water & Ice we are the home of the h2o guru. Ultra pure RO and RODI water experts since 1982!