The Best RO DI Systems for Reef Tank for 2023

best RO DI system for reef tank

Without a doubt, the reverse osmosis water system is specifically intended to filter the water and effectively get rid of various sorts of filth and pollutants so that you can ensure having clean water. That said, it only shows how important it is to invest in the best RO DI system for reef tanks. Having one can guarantee that your reef tank is free of any impurities that could be hazardous in the long run.

Such a tool has been tested and proven to be reliable and efficient in filtering water. And avant-garde technology of today has significantly bolstered the filtration capability to the extent of eliminating up to nearly 100% of the filth. It is good to know that it is made easier to shop for RO DI systems for reef tanks and saltwater aquariums.

Choosing the top-rated RO DI units will require understanding several buying factors. Before we look at the reviews, we must discuss a few important aspects so that you won’t be confused when reading through the rest of this article:

  • Usability of the Unit: It’s never a good idea to purchase an RO system for aquarium tanks without researching the product’s user-friendliness. In other words, you’ll want a unit that makes installing and operating it effortlessly.
  • Filtration Stages and Processes: Each RO/DI water system will have 4-6 filtration stages, depending on the model. So consider carefully what RO filter system aquariums should use to most suit your setup and preferences.
  • Cost: RO/DI systems for reef tanks have a wide range in price. It’d be wise to deal with this variation by constructing a budget based on your needs. This resource will then make dealing with the buying process much more manageable.

It is worth noting that it is critical to ensure that your chosen system is the top-notch option for your fish tank model prior to making the final purchasing decision; otherwise, do not expect it to work reliably and efficiently. This article will share with you some practical buying guides as well as detailed product reviews to assist you as you pick the one that could work most suitable for your needs.

Best Overall

Aquatic Life RO Buddie Reverse Osmosis Systems

Aquatic Life RO Systems

✅ Straightforward and easy to replace
✅ Simple to use and works effectively
✅ Comes with faucet adapter


Premium Choice


LiquaGen 5-Stage Deionization

✅ Long-lasting & super durable
✅ Two-year manufacturer warranty offer
✅ Designed to be BPA-free


Editor’s Choice


Express Water Filtration System

✅ Does wonder in fish tank setup
✅ Quick and easy to set up
✅ Helps you create a safe and better home


Top-Rated RO DI System for Reef Tank Reviews 2023

1. Aquatic Life RO Systems

Aquatic Life RO Buddie Reverse Osmosis Systems

Are you presently hunting down for top quality RO DI water system? Then, you can check this product out and discover how efficient it can be to deliver what was advertised.

This system will help ensure to prevent the possibility of leakage. If you encounter some leaks, then most likely, you are not utilizing the push-pull connectors accordingly. It is highly advised to go over the manufacturer’s instructions carefully to avoid such encounters. The instruction is very clear and precise, it expounds clearly on how to utilize the system and there are even some photos for demonstrations.

Moreover, the carbon, DI cartridges and sediment are quite straightforward and plain sailing to replace. So, even for beginners, this is quite up-front. Once bought, it already comes with a faucet adapter that allows easy linkage to a regular male hose bib or thread. Meanwhile, the usual rejection rate is meant to filter out superfluous ingredients.

However, please be guided that this system is not designed to feed drinking water supplies; for instance, fridge or faucet water supplies. And, hinging on the speed flow, it is between 50 to 100 gallons per hour. Also, this is not meant to cycle larger tanks as it could operate slowly. These are the weak points that must be seriously considered if you plan to buy this product.

  • Straightforward and easy to replace DI cartridges, carbon and sediment
  • Can guarantee exceptional water output
  • Comes with faucet adapter that’s a piece of cake to connect
  • Includes very clear and accurate instructions
  • Very simple to use and works effectively
  • Quite slow to use in cycling larger tanks
  • Not intended for feeding drinking water supplies
Overall, the mount is superb; the entire filter system could be immediately lifted off from the mount and stored away when there is no need to filter water. Setting it up is a breeze even though you may need to adjust a few connections, but after doing so, you’re all set. You won’t have problems with delivery and it can handle beyond two gallons per hour. This is the right pick if you do not wish to suffer from leak problems. And, most importantly, this is a top-notch unit for producing ten by up to fifteen gallons per week.

2. LiquaGen 5-Stage Reverse Osmosis


Would you like to end up buying the best RO DI system for reef tanks? Of course, you sure do. This stuff can work like a charm. It is the ideal choice for lab testing, aquariums and other sorts of applications where uncontaminated water is deemed necessary. This could ensure 0 ppm water, it comes pre-assembled, which allows for effortless setup.

This system is nice and portable, making it smooth sailing to install anywhere you would like it to. It helps make good and soft water for aquariums. It matters to take into consideration that this especially necessitates a minimum of water pressure, just like any other similar options out there. This product is manufactured to be BPA-free which makes it harmless to the planet we live in.

By the same token, what makes it a prominent choice to look into are its superb durability feature and long-lasting filters that can ward off the likelihood of instant breakage or damage.

Nevertheless, a few of the irregularities that must not be taken lightly if you choose this product are its very short tubing, that requires you to purchase extra if you intend to execute a real setup of this unit and the loose fittings that bring about leak issues. You will need to utilize plumbers’ tape in order to get all the connections to fasten accordingly.

  • Long-lasting, super durable and not prone to breakage and damage
  • Highly recommended for city water use
  • Setup process can be done in a snap since it is pre-assembled
  • Supported by two-year manufacturer warranty offer and lifetime customer support
  • Designed to be BPA-free
  • Fittings tend to leak
  • Comes with short tubing
In a nutshell, this is such a good deal for the excellent quality filtration it can offer. It definitely works like a champ. Since it comes with step by step installation instructions, this is a piece of cake to set up. And, it is designed to be portable so you can install it anywhere you prefer to. This is a very solid unit that comes with a few additional connectors for future reference if something needs replacement. As for the price, it is superb! This is ideal if you have a fish tank that contains 70 gallons of water or lower than that.

3. Express Water Filtration System


Without question, deionized water is ideal for appliances and helps make pollutant-free foods and drinks; hence, it is just right that you conduct research about effective and reliable RO DI water systems that could help you achieve all these. Additionally, this product can help you come up with a fantastic fish tank setup since it can help your aquarium pets and plants to thrive and sustain a healthy and longer life inside the tank.

This system works superbly when it comes to ensuring that all filters are meticulously built to work together and be capable of producing the safest and top-tasting water that you could ever consume. In short, this provides you with the kind of water that you need precisely. Since this is uncomplicated to install, you won’t even need professional help to complete the installation process. This comes with easy-to-follow instructions that even beginners can handle.

For all that, a couple of the drawbacks that you need to inspect when purchasing this product are its loose fittings which are the root causes of possible leak issues and unlike other similar products out there, this tends to recharge a little slower.

  • Helps you create a safe and better home with clean drinking water
  • Does wonders in fish tank setup
  • Manufactured with filters that perform at their best
  • Quick and easy to set up
  • Automatically supplies your water tank with super clean and safe drinking water
  • Tends to recharge slightly slower
  • Factory fittings are not tight

Once and for all, this RO DI system is not burdensome to set up and comes with easy to understand instructions. Compared with other similar options, this comes complete and is a certified well-packaged kit that includes all the things you especially need for installation. It guarantees zero ppm and it does a great job of helping you automatically fill your tank with superb quality drinking water. You do not even have to mess with activating or replenishing the system.

As you can see, there is no reason for you to search further since this manufacturer has gone above and beyond to deliver what was advertised. For the money, this is a great deal that you must not miss.

4. LiquaGen Portable Water System


If you are in search of a two-in-one and pre-assembled RO/DI system, then you need not look elsewhere. This product is admirable and practical in a lot of ways, making it one of the most preferred options for wise consumers, homeowners and aquarium owners.

There is no need for you to invest in two systems mainly because this stuff is designed to be dual purpose. It comes pre-assembled and manufactured with two outlets that enable dual uses. The first outlet is meant for drinking water which means it is safe to use when you’re preparing and cooking food. Meanwhile, the second outlet is intended for lab testing, fish tanks, and other uses where impurity-free water is literally required.

This helps enhance the qualities of contaminant-free water by adding health minerals and other vital minerals to encourage proper human development that is readily existing in a number of natural mineral waters.

Howbeit, the complaints you may have for this stuff are the uninstalled hose barbs and retaining clips. Apart from this, it may consume more time to set it up it calls for being taken apart and resealed. So, you better strictly follow the manufacturer’s installation.

  • Significantly aids in renewing minerals lost in the reverse osmosis process
  • Certified superb two-in-one system
  • Especially built with High Rejection Reverse Osmosis (RO) Membrane
  • Designed with manual flush valve
  • Comes pre-assembled, so installation is a breeze
  • Uninstalled retaining clips and hose barbs
  • May take a while to set up if it needs to be disassembled and resealed
Conclusively, this RO/DI unit is a good value for the money. It comes with a manual flush valve that makes it unmatched by any other similar products in the market. What makes it quite distinguished from the rest is its capability to increase the lifespan of the unit, remarkably minimize the potentiality of leaks and help you save more time when cleansing the system every few months. This is a great unit and the replacement filters are first-rate. You can fully rely on it to eradicate filth from water. And, it is not a pain in the neck to set up since it is a pre-assembled system already.

5. AquaFX RO/DI Aquarium Filter


If you are looking for a top-quality RO DI unit reef tank that already includes all the necessary things you need in order to keep your tank water clean, then this could be your most acceptable buddy to execute the job.

This system will certainly work well for an aquarium setup. It is constructed with sterling build quality that proves its long-lasting durability. Aside from this, it also comes with a pressure meter. Once bought, this comes ready to utilize and all you need to do is to ensure that the RO membrane is inserted and you are all set. You need to keep in mind though that your mileage will differ hinging on your water temperature, water pressure as well as starting TDS.

In like manner, this product features superior flow and superior rejection TFC membrane. It also comes with a pressure gauge and hose bib adapter. All things about this system are well-made and enable a simple solution for impurity-free water. This has made caring for and maintenance for the reef tank a headache-free process. There is no need to run to the store to get clean water and this is highly practical to be considered for anyone keeping a fish tank.

Notwithstanding, a few of the minor gripes that you need to be aware of include the lack of control vale or flow restrictor and it seems that their customer service support is not that helpful at all as they could be hard to reach.

  • Already includes a two-micron chlorine guzzler carbon block filter
  • Comes with ¼†hose bib adapter once purchased
  • Can guarantee zero leaks
  • Designed with superior flow and superior rejection TFC membrane
  • Manufactured with outstanding build quality
  • Unresponsive customer service support
  • Does not come with control valve or flow restrictor
All in all, this product itself is not anything unusual; however, it comes with everything you specifically require and it is capable of producing 0 TDS water. Not only that, it can surprisingly hook up to a standard hose screw with the adapter and it starts to operate quite well once you get it going. While it is slightly slower than the 100 GPD rating, this is still speedy enough to get the job accomplished. As for the build quality, this is unrivaled and is powerful enough to fill a five-gallon canister in just a matter of one hour.



Are you seeking to sure-buy aquarium RO systems? Then, you may start unveiling what this unit can do for you.

In reality, what makes this a great choice that you should not ignore are its several stellar features and superior performance. It is manufactured with a six-stage RO/DI aquarium system, 2 DI refillable color-altering media cartridges and 150 GPD membrane. Once purchased, it also includes all clear housings.

What’s more, a continuous supply of high-purity water could be acquired through the use of the 2 cartridges in series and enabling the first cartridge to decrease fully. It is during this operation that the second cartridge guarantees that the water escaping the system is of the most superior purity.

Meanwhile, the clear cartridges can be refilled. Thus, you can avoid the pricey cost of purchasing media in bulk and utilize the inline cartridges repeatedly.

However, there are a few minor concerns that must be inspected if you are looking to purchase this unit. First, it comes with a pricey selling cost, so if you have a tight budget, you may need to save some more before purchasing it. Secondly, the seal tends to cause leaks or drips, so you need to install them properly.

  • Premium quality six-stage RO/DI aquarium system
  • Can offer you the lowest possible total dissolved solids reading
  • Comes with dual DI refillable color altering media cartridges
  • Capable of guaranteeing consistent supply of high-purity water
  • Includes all clear housings
  • Not ideal option for anyone with tight budget
  • Tendency for the seal to cause drips or leaks
On the button, this reverse osmosis system, consolidated with a DI after the filter, would provide you the lowest total dissolved solids reading for your fish tank water supply. It is essential to understand that DI resin is required to decrease TDS to 0 and is known as the final phase of an RO/DI unit. Likewise, it is useless to utilize the costly proprietary DI cartridges that other RO manufacturers offer in the market nowadays. All you need to do is to solely purchase a refillable DI cartridge and put in DI resin. This way, you could set aside some bucks and enjoy the same outcomes.

Outdated Products

Koolermax RO+DI Aquarium Reef RO System (Outdated)


This RO DI system for aquarium is manufactured with a six-stage RO+DO aquarium reef water RO system. Besides, it is built with an auto-shutdown valve wherein once the output is closed; automatically the input will shut off. This product is a great investment that you can bank on since FDA and NSF approve its components. It is noteworthy to know that this product is recognized for being a great unit for fish hobbyists.

If it is your first time buying and setting up one, there is no need to worry about handling the task because this comes pre-assembled already. All you need to do is to fasten the tubing to the appropriate spots. You’ll discover for yourself how easy it is to set up and the instructions are quite brief yet precise so you won’t go wrong.

Furthermore, once bought, this stuff already comes with the required hardware for installation, the top-quality RO unit, all filters as well as a pressure gauge. And, since it has the capability to read operating pressure, users can easily determine the right time when to replace the three underneath filters.

Withal, some consumers do not prefer this unit because it comes with small resin particularly if your TDS is more than 300 for your faucet. In addition to this, their filters are overpriced and the delivery fee seems unreasonable.

  • Package includes pressure gauge, installation hardware, RO unit and all filters
  • Components are approved by FDA and NSF
  • Designed with auto-shut-down valve
  • Backed up by one-year warranty offer
  • Capable of reading operating pressure
  • Too tiny resin
  • Too expensive filters
Lastly, this unit is pretty great for those searching for a beginning point of producing deionized water. It comes with a straightforward setup, can minimize the dissolved solids in tap water quite superbly, it helps get rid of 98% of dissolved minerals and pollutants, eliminates chlorine rate, odor and chloramines and significantly aids purifying and lessening the minerals for fish tanks or other purposes. As you can see, its six-stage are quite unique and stellar. This is definitely the top-tier bang for the money.

LiquaGen Deionization Reverse Osmosis Water Filter Systems (Outdated)


It is no doubt that investing in an A1 reverse osmosis system for saltwater aquariums is quite daunting especially for first-timers. But, this won’t be the case if you give this product a chance to prove how effective, topnotch and outstanding it is in providing you with clean and safe water.

This unit is quite distinctive from the rest because it has the capability to extend the life of the device, it does a practical job of diminishing potential leaks and there is no need to waste more time flushing the system every few months. You can utilize it if you are keeping a reef tank, freshwater or saltwater aquarium, lab testing and other uses where clean and clear water is the top priority.

Also, this is built with High Rejection Reverse Osmosis (RO) Membrane. And, there is no reason for you to have second thoughts about whether to get it or not because this is a risk-free investment that you can consider. It is supported by a two-year warranty and you can also delight in their lifetime customer support program.

Generally, two demerits that must be taken care of regarding this product are its costly price tag that would surely put a hole in your pocket, especially if you have a tight budget. And, you need to ensure that you follow the manufacturer’s instructions accordingly. Otherwise, this would be cumbersome to install.

  • Harmless to the environment
  • Supported by two-year warranty
  • Manufactured with manual flush valve
  • Friendly and beneficial to various marine species and aquatic plants
  • Highly recommended for saltwater and freshwater aquariums and reef tanks
  • Not budget-friendly
  • A little tricky to set up
In the end, even if this unit is not priced reasonably, you will realize that it is well worth every single cent you pay for it. This product is the solution to enhance the quality of your saltwater aquarium tremendously. It comes with solid build and already includes an intake adapter from a hose connector and a float shutoff valve that you can easily connect to a container. You can possibly move it from container to container every hour or so. And, it can practically shut off well when it’s full. It was well-constructed with the fish tank user in mind.

Aquatic Life Twist-In 3-Stage Ro Unit (Outdated)


This RO DI filter is deemed as one of the most favorite options by countless of consumers precisely because it is manufactured with twist-in cartridges that allow instant and effortless replacement of filter media. It is good to note that the cartridges are not that difficult to embed so long as you have the unit mounted. This product also comes with triple-sealed cartridges that are meant to guarantee smooth operation.

It is delightful to note that many consumers who once had some concerns buying this product have claimed that this product is backed up by very responsive and helpful customer service support. Thus, if you encounter some issues, you can always count on their assistance.

Even so, this system comes with very short storage caps that could be tough to manage. And, if you are currently residing in New York City, this system especially requires pre-filtration before use due to very high city water sediment issues.

  • Comes with top-drawer customer service support
  • Step by step and detailed instructions
  • Compact, lightweight and convenient
  • Guarantees hassle-free and fast replacement of filter media
  • Great value for the money
  • Requires pre-filtration before use in New York City
  • Comes with very short storage caps

Right to it, this RO.DI is a stellar system at a good price point. It is straightforward to install, so easy to utilize and makes water come up with 0 total dissolved solids. You’ll love the fact that it is lightweight, compact and a lot more convenient to work with. The Di resin eliminates TDS and alters color when it is high time to replace. Once bought, this includes all the accessories needed for setup processes such as the drain connector, water supply connectors and tubing. As you can see, everything you need is all set.

Besides this also includes a deionization filter, membrane, carbon filter and sediment filter. And, the best of all, for the price, this is quite cost-effective in that it already includes all the things you will ever need to set the system up. Hence, this helps save more time and money in the process.

LiquaGen Aquarium-Countertop Reverse Osmosis Water Filter System (Outdated)


Undoubtedly, this product can be perceived as one of the top-tier reverse osmosis systems for aquariums. It is quite practical to utilize for fish tanks, lab testing and other uses that seriously calls for pollutant-free water. Thus, whether you need a system that you can safely use for saltwater and freshwater tanks or reef tanks, this stuff won’t leave you feeling dismayed.

If you are keeping a freshwater or saltwater aquarium or reef tank, then this could be one of the top-picks for you. This can look after various fish species and aquatic plants in your tank. Since this system is particularly designed to be compact and lightweight, you can move it around anytime and anywhere.

Not to mention, this is ideal for those who would like to invest in a RO DI system for the first time and seriously necessitate getting rid of tiny pollutants such as chlorine unearthed in city water. Basically, this does not need a huge space so it is good if you don’t have a big space in your place.

All the same, a few of the weak points that you must watch for if you have plans to purchase this product are the loose fittings that could cause leaks and lead to wasting more water. Indeed, it is a little slower than the production rate the manufacturer has promised.

  • Guarantees 0 ppm water
  • Environmentally-friendly since it is free of BPA components
  • Comes complete with all required connections, tubing and faucet adapter
  • Manufactured with premium quality and super durable filters
  • Harmless to various marine life and plants
  • Slightly slower as compared to the production rate advertised
  • Fittings tend to leak
To conclude, this system is great for a number of applications. Aside from its excellence in purifying the water for reef tanks, this also does a superb job of clearing the water of any impurities or pollutants, making it safer to drink and use for many household purposes. If you have it installed, the water quality after examining contains no trace of silicates, phosphates, nitrates, nitrites, ammonia and the like. This stuff is extraordinary in terms of meeting all its expectations so it is undeniably highly commendable.

What To Look For When Buying An RO DI System For Reef Tank

best reverse osmosis system for aquarium

Needless to say, shopping for the right RO DI system for you is not merely about picking just about anything that you can come across on local marine supply stores, hardware or online shopping sites. Of course, if you would like to ensure getting the real value of your money, administering a little research can help you ward off the possibility of buying the unsuitable option for you.

Some RO DI system buying considerations that you need to keep in mind include the following:

Certifications and Brand

Top-notch brands have a good reputation that needs to be maintained. So, if the brand of your choice is reputable, you can surely end up buying the right unit. Hence, before taking the plunge, see to it to conduct research first about the top-rated brands in the field.

Be that as it may, aside from purchasing from the most trusted manufacturer, it is a must to ensure that the filter comes with appropriate certifications. The most typical certifications include NSF and FDA certificates. You can rest assure that you have chosen the right unit it is certified by NSF and FDA.

Usability of the Unit

Avoid buying units that consume a lot of time for installation, configuration and operation. As much as possible, opt for the ones that come pre-assembled and already include all the installation tools, accessories and hardware needed. Pick the one that is manufactured with user-friendly controls. As you might already know, controls are the ones that allow users to operate the system and create contaminant-free water for your fish tank.

Filtration Stages and Processes

RO/DI water systems are built with different filtration stages, specifically 4 to 6 filtration stages. The stages are the ones that tell about water purification. This indicates how purified your water is, how safe it is for your reef tank and if it is completely free of pollutants.

Such systems generally come with additional filters that eliminate foul odor and enhance the taste of water.

Setup Process and Maintenance

Hinging on the design, different filter systems could be either intricate or a piece of cake to set up. Of course, go for the one that is not difficult to install and maintain. Some options come complete and include all necessary accessories for setup.

If the RO/DI unit of your choice is easy to install, it will also be easy to replace and maintain in case there is breakage.

Other Important Factors to Consider

ro di water system

What is an RO DI system for reef tank?

RO pertains to reverse osmosis and the acronym RO DI refers to reverse osmosis deionization that is identified as the reverse osmosis system that comes with an additional DI stage of filtration, which is designed to filter tap water down to total dissolved solids (TDS).

Such a system is highly practical to utilize for freshwater fish tanks, and it is crucial to use RO/DI system for combining saltwater and for refilling freshwater lost brought about marine tank evaporation.

A reverse osmosis water system is specifically designed to filter the water, particularly to eradicate any pollutants in order to have contaminant-free water effectively. This comes in distinct shapes, sizes and functionality. So, it is imperative to know what aquarium model you are currently keeping before you get one.

How does it work?

RO DI systems operate by eradicating chlorine and sediment from water with the aid of a pre-filter prior, it compels the water through a semi-penetrable membrane to get rid of dissolved solids. And, right after the water leaves the RO membrane, this moves through a post-filter to significantly enhance the drinking water prior it infiltrating a designated faucet.

Fundamentally, RO systems come with different phases hinging on their number of pre-filters and post-filters.

What are the different types of RO DI systems?

There are several types of RO DI systems and deionization filtration devices sold on the market these days; all these are virtually manufactured to auspiciously match the performance level you necessitate, the fish tank you are presently utilizing and all available within the amount of money you are more than willing to spend.

It is critical to take a detailed look into what type of RO DI system you prefer and the features you seriously require and from there, you can ensure that you are picking the RO DI filtration system that would cater to your current needs.

It is highly advised to go for multi-stage RO DI systems. Some RO DI units operate with at least a four-stage process. Meanwhile, there are others that are designed with five to six stages.

Why do you need an RO DI system for saltwater aquarium?

It is substantial to note that a reverse osmosis system is regarded as one of the most exhaustive and thorough approaches to filtration. This remarkably helps in getting rid of 98% of dissolved solids that make the water safer and more nutrient-filled to drink and use for other purposes. Indeed, a water distiller is the particular other drinking water system that also operates to decrease total dissolved solids; nonetheless, it is less effective than an RO system.

Getting a RO DI system can offer you the following perks:

  • Work to decrease the amount of sodium efficiently
  • RO DI systems are known to be harmless to the planet we live in so it is friendly to marine pets and aquatic plants
  • Permanently eliminate hazardous dissolved pollutants
  • More plain sailing to set up and maintain than other water filtration systems out there
  • Can tremendously get rid of the water’s unpleasant smell and horrible taste
  • Most of them are compact, lightweight and portable
  • Can look after your aquarium inhabitants such as various fish species and live aquatic plants
  • These are ideal to use for reef tanks, freshwater and saltwater aquariums.

It is a must to use a RO DI system for your saltwater aquarium because reverse osmosis generates high-purity water that is free of any hazardous chemicals such as toxins and chlorine. And, aside from this, it also does a good job of eradicating up to 99% of dissolved solids that are present in your water.

Indeed, this provides a balanced environment for you to form the best possible conditions for your marine pets and aquatic plants to grow and live healthily inside the tank. Reverse osmosis water enables you to come up with accurate water conditions that will top-tier fit your fish tank, unregulated by your local water quality.

Virtually, reverse osmosis expels nitrates, dissolved minerals, heavy metals and salts from water. This results in unmatched purity and an unsurpassable blank slate from which you can create a thriving fish tank environment. More than that, the water is prepped to be restored to the precise parameters your marine pets especially require.

And, reverse osmosis offers you complete control over your water’s salt content, pH level, and what minerals your marine life will be exposed to. This is one great way to make the stabilization of your fish tank less hassle and uncomplicated at.

Frequently Asked Questions


What is the difference between RO and RO DI?

RO/DI and RO units for aquariums only have one primary difference. RO/DI water systems offer an additional filtration stage called deionization. Otherwise, these two systems don’t differ in any particular way.

But this extra filtration stage is critical for bringing water TDS to zero. It’s what makes RODI water filtration ideal for a reef aquarium setup.

LiquaGen’s 5-Stage Reverse Osmosis and Deionization would be a perfect example. By offering this additional step, it separates itself from other portable RO system models. So this compact RO/DI system will have no trouble creating an ideal reef environment for clownfish or other reef critters.

Does RO DI remove chlorine?

RO/DI units for aquariums do remove chlorine and sediment from your tank’s water. It’s a significant step in their filtration process to ensure your fish are as comfy as possible. So any top-rated option won’t have any problems dealing with chlorine.

In particular, Koolermax’s RO+DI Aquarium Reef RO System has an excellent reputation for eliminating chlorine from the city or well water. It also does quite an excellent job of removing odors, chloramines, and dissolved minerals.

Can I use distilled water instead of RODI?

Using distilled water as a substitute for an RO/DI or RO filter system isn’t smart. In fact, it’s downright dangerous for the fish inside your tank. Distilled water doesn’t provide the necessary qualities, such as essential nutrients, offered by these other systems.

As a result, it could create an unstable living situation and hurt aquatic creatures. So anyone with a freshwater aquarium must stick with an RO/DI or RO system. Otherwise, you aren’t creating a satisfactory environment for your fish.

How often do you change RO DI?

RO/DI systems will require keeping track of various parts. But generally, you can expect the carbon, sediment, and DI cartridges to stay on the same schedule. These cartridges will often provide at least six months of usage before needing a change.

Once the abovementioned components hit the 6-month mark, I recommend changing them immediately. It’s what I do to prevent any mishaps or issues. Thankfully, I haven’t had a single problem yet with my RO/DI system.

As for the TFC membrane, most experts suggest changing it every two years. So I’d recommend setting a reminder for yourself about it. If you’re anything like me, you’ll forget to change it without that notification.

What are the most trusted RO DI system brands?

When it comes to buying RO/DI unit systems, a few of the most trusted and reliable brands that you can completely back on include:

  1. LiquaGen
  2. Aquatic Life
  3. Koolermax
  4. Fountainhead Water System

These brands have created a good reputation in the field of purifying water. As a matter of fact, many smart consumers prefer these manufacturers because they are quite renowned for producing superb quality products that are manufactured using top quality construction materials, can guarantee stellar performance and can provide long-standing service. And, when it comes to filtering contaminants and other sorts of filth in the water, these brands have been tested and proven to exceed the expectation of their customers around the globe.

How to care & clean?

When it comes to cleaning, caring for and maintaining RO/DI systems, you need to take note that each phase of your RO DI filters specifically calls for replacement so that you can successfully keep your system in supreme operation. And, this is to extend its lifespan as well.

Substantially, if the system is not periodically maintained, the RO DI system could generate less water and total dissolved solids can literally transpire through the system. Luckily, what’s practical about these units is that they are meant to last for a longer period of usage as these are perceived as the most dependable systems and chief support in your water and reef tank operations.

What is the warranty?

As for the warranty, you may learn more information about this by checking the product description. However, if the warranty details are not clearly indicated in the product information section, another way of checking this out is by contacting the manufacturer’s customer support service. You can do so by sending them an email, through chat support, or by phone.

Nonetheless, the RO DI system for reef tanks reviewed in this post is all backed up by different warranties that consumers can benefit from. Such warranties consist of money refunds, replacements of wrong or faulty items and limited or lifetime warranty offers.

In case you observe that the product does not come with a warranty, then it is highly advised to skip it and search for other options available.

Where to buy?

You can shop for top quality RO DI system for reef tank in nearby local marine supply stores in your current location or well-stocked hardware stores. However, it is uncertain if you can select from numerous choices since buying them locally generally offers limited options only. In other words, some other top-notch brands may not be available in such stores.

Anyhow, shopping for them online can offer you with more options to choose from. And, the delightful news is that you can find many word-class brands too especially if you shop in legit and the world’s most trusted online shopping sites such as Amazon. Not only that, there are some freebies, special promos and discounts when you buy a specific amount that you could avail of as well.

How long do reverse osmosis systems last?

These units generally come with an extended lifespan; notwithstanding, the filters, as well as the RO membrane calls for replacements on a regular mode. Please be guided that pre-filters and post-filters must be replaced every six months by up to one year.

Meanwhile, depending on the conditions of your water, the RO membrane must be changed every two by up to four years.

What does reverse osmosis system expel besides the ones mentioned previously?

Apart from the aforesaid contaminants that reverse osmosis eliminates consist of fluoride, arsenic, pesticides and herbicides, sediments, VOCs and many other sorts of pollutants.


In summary, from the various options you have come across above, you surely have learned that there are several vital factors to ponder when picking the best RO DI system for reef tanks. As you have read in this article, these systems are capable of delivering the superb performance that you especially require when you make a perfect choice and invest in the most appropriate model.

Unquestionably, comparing distinct models is generally the most excellent approach to end up with RO DI system that can cater to your needs. Having the right one would help you better manage any contaminants and filth in your aquarium water. These come in different functionalities, shapes and sizes. Luckily, there is no need to purchase all of them; all you need to do is to ensure to get the one that works most suitable for your tank.

In substance, the main objective of this post is to help you learn more about what makes premium quality RO DI systems for aquariums. And, being provided with detailed product reviews, you can now easily compare what’s practical and what’s not. Thus, the information tackled above can help you guarantee a worthwhile investment that you won’t ever regret.