Best Reverse Osmosis System For Aquariums

Best reverse osmosis system for aquariums is the most useful investment to make, for your tank. Best thing you can even use the water for regular other works.

I assume you have a good filter assembly to purify your aquarium so that your fishes can swim in an appropriate underwater environment without the chances of getting sick. And be sure adding RO would be the next best thing you can do for your fishes.

How Can An RO System Add Protection And Decrease Tank Cleaning Frequency?

If you think about it carefully,  then it is actually a great idea to keep your tank water safer for your fishes. As the aquarium water keeps evaporating, the Total Dissolved Solids in the water will increase, and even the high-quality filters struggle to remove it properly.

Also, the quality of your tap water will fluctuate throughout the year and it will be difficult for your cleaning system to clean the water properly. So if you consider having your tap water clean with the help of the reverse osmosis filter for aquarium first, then all the dissolved inorganic solids will be removed through the semipermeable membrane in the filter.

Some of the aquarium RO system filters also have 3 or more stages of unit to clean the water deeply from all kind of dissolved unwanted substances, so that your aquatic lives can live a healthy life. Here are the top 7 aquarium RO system on the market that you can have for better cleaning of the water.

Best Reverse Osmosis System Reviews For Aquarium

A lot of people get confused while selecting these devices. So we made sure to pick the best ones and hand it over to you for the final choice out of hundreds available online and offline. The devices are sorted in decreasing order and hence you can select as per your choice. All of them are in the best category.

1. AquaFX Barracuda RO/DI Aquarium Filter

No matter how hard you try to keep your fishes in a good health, somehow everything gets messed up. If this is the case then maybe you are in need of a Reverse Osmosis for aquariums which will clean all the dissolved organic impurities and harmful chemicals from the tank water.

AquaFX Barracuda RO/DI Aquarium FilterIt is true that saltwater tanks are in need of more care than the freshwater aquariums.

Hence, in order to give your reef tank or your marine tank the best water condition so that your marine lives can have the most suitable underwater environment, this 4 stage salt water reverse osmosis system for aquariums is a must have.

However, this aquarium RO system even goes highly effective with freshwater aquariums also.


With the help of advanced technology, this marine reverse osmosis system has been upgraded with high-quality material and efficiency to match the requirements of a user.

I can bet that the features this aquarium RO system has will leave you amazed and you can’t help but have this system of reverse osmosis water for fish.

The impressing features of this RO system for aquarium are-

  • The AquaFX Barracuda Reverse Osmosis Deionization System is equipped with 4 stage RO units which help in removing all the dissolved inorganic impurities in the tap water.
  • Stage – 1: The 1-micron sediment filter traps all the particles of 1 micron and large to purify the water.
  • Stage – 2:  The AquaFX 2-micron Carbon block filter uses chemical adsorption to remove contaminants and impurities including chlorine, sediment, volatile organic compounds (VOCs), and odor from water.
  • Stage –  3: The High Flow / High Rejection AquaFX TFC Membrane is highly efficient in removing silicates.
  • Stage – 4:  The AquaFX Virgin Color-indicating DI resin cartridge helps the user to understand when all the resin in the water has been removed by changing color.
  • The 160 Pound Per Square Inch pressure gauge indicates you the remaining capacity of the filter each time you use.
  • The metal bracket of this aquarium RO water system is made of rust-proof solid aluminum.
  • 10 inches of filter cartridge housing.
  • All the systems include quick connect fittings and a filter wrench for easy cartridge replacement.
  • This kit is available in 50 and 100 GPD Membrane.
  • The dimensions of the product are 20 x 18 x 8 inches.
  • Total weight of the product is 12 pounds.

Last Verdict:

The 4 stage aquarium RO system of AquaFX is highly efficient in removing dissolved inorganic solids including, fluoride, chlorine, chloramine, detergents, lead, pesticides, nitrates, and sulfates, hence making the tap water absolutely suitable for your fishes. (Read this if you want to only remove chlorine from tap water)

The high quality of the aquarium RO system and the well-built efficiency are undeniable to any aquarist, which is why this best reverse osmosis system for aquarium from AquaFX will always be in the first position of my recommendation list.

View The Product Now

2. 6-Stage Aquarium Reef Reverse Osmosis Water Filter System 

Though both freshwater and marine water aquariums are in need of proper filtration, reef aquariums demand a special care. In order to get colorful and vibrant reefs you definitely need to take care of the filtration process of the water as reefs are highly sensitive to the increase of Total Dissolved Solids or TDS.

6-Stage Aquarium Reef Reverse Osmosis Water Filter System (RO/DI) | 100 GPD MembraneControlling the TDS properly or having reverse osmosis water for aquarium can only be accomplished through running your tap water into an aquarium RO system and then filling up the tank with it.

So without asking, ‘how to make RO water for marine fish’, have this aquarium RO system as it is highly capable of minimizing the amount of Total Dissolved Solids in the tank water.

This 6 stage Aquarium Reef aquarium RO system is manufactured by LiquaGen with the mission to help the reef tank owners in getting RO water each time they top up the aquarium so that the reefs can thrive well for years.


The 6 stage aquarium RO system is highly capable of clearing the water from dissolved inorganic solids like salts, fluoride, pesticides, nitrates, sulfates, lead, chloramine etc. LiquaGen has filled this kit with many useful features, all of which are essential in achieving better health for your reefs or fishes.

The 6 stages of this Aquarium Reef Reverse Osmosis System from LiquaGen includes –

  • Stage – 1: 5 Micron Sediment Block which traps particles of 5-micron and larger in order to make the water safe.
  • Stage – 2: The carbon block filter helps in absorption of the Volatile Organic Compounds, chloride, sediment etc.
  • Stage – 3: The UDF carbon filter to keep the water polished.
  • Stage – 4: The semipermeable membrane of 100 GPD only allows small molecules like H20 to pass.
  • Stage – 5: Inline Deionization filter to trap salts.
  • Stage – 6: Inline Deionization Color changing filter.
  • Other than that this kit is included with filter wrench, Inline Ball Valve and FDA Approved Color Graded Tubing.
  • The aquarium RO system is pre-assembled for the ease of installation.
  • The kit comes with the guarantee of zero Total Dissolved Solids.
  • The aquarium RO system is built in the USA with 100% Satisfaction Guarantee.
  • The system is pressure tested to ensure highest standards of quality.
  • The manual flush valve makes this fish tank RO system more durable reducing possible leakage.
  • The kit comes with 2 years of manufacturer warranty and lifetime customer support.
  • The dimensions of the fish tank reverse osmosis system are 17 x 5 x 15 inches.
  • Total weight of the kit is 13.5 pounds.

Last Verdict:

This is agreeably one of the most highly effective reverse osmosis systems to have. So in order to get a complete system to purify your tap water for your fishes or reefs, you should always consider this kit as one of your best buying choices.

Other than that the 2 years of manufacturer warranty indicates the quality and durability of the product, so overall it will definitely be a cost-effective deal for you.

View The Product Now

3. Countertop Portable Universal 5-stage Reverse Osmosis System

Undoubtedly Reverse Osmosis or RO systems are the best in terms of purifying the fish tank water but if you get a portable kit then it will certainly be a great deal for you. Since the weight of the system will be easy to carry, the question will arise that how efficient will be the kit?

Countertop Portable Universal 5-stage Reverse Osmosis RO Purification Water System with DI Deionizing Mixed Bed 0PPM postfilter, made in USAKeeping the efficiency of the product in the number one position, the manufacturer has made a durable product with 5 stages of RO filtration unit which will help you to purify your tap water with absolute accuracy.


To determine how effectively an best reverse osmosis system works, you can look at its features as the best RO filters on the market have the most useful features. The Countertop Portable Universal 5 stage Reverse Osmosis System has been incorporated with the below features which are undoubtedly useful for the aquarists.

  • Stage – 1: The premium quick-connect 5-micron sediment filter traps dust and rust particles of 5 microns and larger to extend the life of the system and membrane, apart from purifying the water.
  • Stage – 2: The quick-connect T28 coconut activated carbon filter removes volatile organic compounds, and other substances like chlorine, cloudiness, offensive, colors, odors and bad tastes.
  • Stage – 3: The reverse osmosis membrane of 75 GPD is made of high rejection thin film composite to strain unwanted solids up to 99%. Arsenic, lead, fluoride, chromium, radium, viruses, bacteria, and other unhealthy contaminants are also removed at this stage.
  • Stage – 4: With the help of the deionizing mixed bed polishing filters the kit produces ultra high-quality water on a continuous basis.
  • Stage – 5:  After going through all the stages the US made T33 post polishing filter polishes the water for the final step.
  • This great reverse osmosis system easily attaches to your kitchen faucet without the need of help from any plumber.
  • This Reverse Osmosis kit is very easy to portable.
  • The total weight of the semi permeable system is 5 pounds.

Last Verdict:

This is altogether an excellent system to clean the tap water from the impurities. This kit makes the tap water absolutely safe for your aquatic lives hence a good choice to start with. Also, using RO water is an essential part of fish keeping so no matter how good quality filtering system, you definitely need an RO filtration before filling up the tank.

According to me, the portability is a great feature, to have in an RO filter. Hence, a great buy for those who travel every now and then.

View The Product Now

4. Koolermax AR-122 6-stage Aquarium Reef RO+DI system

Koolermax has introduced this RO and DI system especially for the Reef and marine tanks. However, you can also clean your water for the freshwater tank. The best part of this system is that it has been incorporated with 6 stages of RO unit.

Koolermax AR-122 6-stage RO+DI Aquarium Reef RO system 80 to 120 GPD New completeThese 6 stages help in purifying the water with high efficiency so that the water becomes safe enough to keep marine or aquatic lives. This kit comes at a really affordable price yet has all the abilities to deep clean the water.

As the quality of the tap water vary all the year long, to make your fishes habituated with a certain type of water do not forget to clean the water with RO unit to get an absolutely suitable underwater environment for your fishes.


The features of a product determine the quality of the product or how the product is going to be beneficial for the user. Not all the RO and DI systems on the market are suitable to incorporate with your tank water rather you have to be very picky when it comes to having such high-efficiency products.

Below are the features that make this kit a worth buying one.

  • Koolermax is manufacturing RO system in California USA for 18 years now, hence they are well equipped with high-end manufacturing.
  • The absolutely reliable and guaranteed systems to have for your tank comes with 1-year warranty.
  • This 6 stage RO and DI filter purify 80 – 120 gallons of water per day depending on the pressure of the water hence the perfect RO for bigger reef or fish tanks.
  • The system also comes complete with all filters and membrane, tubing, installation hardware, pressure gauge and free tech support.
  • Stage – 1: The 5-micron sediment filter clears dust and rust particles of 5 microns and larger.
  • Stage – 2: The coconut shell activated carbon block filter helps in removing chlorine, chloramines, odor taste etc.
  • Stage – 3: In the third stage the filter works hard to remove 100% chlorine.
  • Stage – 4: The 120 GPD reverse osmosis membrane removes up to 98% of dissolved inorganic solids and contaminants.
  • Stage 5  & 6: In these two stages the DI filter purifies and reduces the minerals for the proper output of clear water.
  • The dimensions of the RO unit are 16 x 6 x 16 inches.
  • The kit is assembled in the USA with the approval from NSF and FDA.
  • There is an auto shut-off valve so that when the output is closed the input will be turned off.
  • The total weight of the product is 17 pounds.

Last Verdict:

Koolermax is a big brand which manufactures RO and DI system for 18 years now and the quality and efficiency of the product they have gained them a huge base of fans. So while buying from this manufacturer you will be assured by the fact that, you will get a quality product with unquestionable filtration accuracy.

Overall, the price of the kit is also affordable which is why I will definitely recommend you to have this RO system for your marine or freshwater tank.

View The Product Now

5. Purewaterclub 0PPM Portable 150 GPD Reverse Osmosis RO+DI System

While tap water is safe for cooking, it can be harmful to your fishes as there are some dissolved solids that can change the chemistry of the water and your fishes may get sick or die. In that case, the filter also cannot help because apart from cleaning the water from organic compounds, there are some harmful particles which still remains in the water.

0PPM Portable 150 GPD Reverse Osmosis RO+DI Filtration POQ-4B-150To get rid of such unwanted solids and decrease the amount of Total Dissolved Solid or TDS you need to run your water through the several stages of Reverse Osmosis and Deionization system so that the water get cleaned up deeply from all types of impurities.

The 150 GPD Reverse Osmosis and Deionization system from Purewaterclub is one such system that can help you to have a safe environment for your fishes. Also, the ease of portability makes this system worth buying.


The features this kit have are very useful for any aquarist and when it comes to the quality and durability, this RO system from Purewaterclub definitely stands out from the rest of its competitors.

  • Stage – 1: 5 Micron Sediment Block which traps particles of 5 microns and larger in order to make the water safe.
  • Stage – 2: The carbon block filter helps in absorption of the Volatile Organic Compounds, chloride, sediment etc.
  • Stage – 3: The UDF carbon filter to keep the water polished.
  • Stage – 4: The semipermeable membrane of 150 GPD only allows small molecules like H20 to pass.
  • Stage – 5: Inline Deionization filter to trap salts.
  • Stage – 6: Inline Deionization Color changing filter.
  • The package includes all filters, membrane and a sink faucet.
  • This 4 stage RO and DI system is easy to portable because of its incredible built.
  • The 12 ft ¼ inch RO tube is included for installation.
  • The kit is absolutely suitable for making 0 PPM water for your fish tank and generates the pure water at 35 PSI.
  • The pre-filter has the ability to work for 6 – 12 months and create the 2000 – 4000 gallons of pure water.
  • The TFC membrane can work for 24 to 36 months and create 54000 to 11000 gallons of pure water.
  • The DI filter has the ability to work for 400 – 500 Gallons.
  • If you are using a flow restrictor of 450 ml with 65 PSI at 25 degrees Celcius, the ratio of the pure water to waste water generation is 1:3.
  • The system is capable of removing 99% of all mercury, calcium, phosphate, Sodium, zinc, chloride, aluminum, lead, copper, arsenic, iron, and magnesium.
  • It also removes 99% of bacteria from the water.

Last Verdict:

If you are thinking of having an RO and DI filter to keep your tap water free from all kind of unwanted dissolved solids both for drinking and to fill your aquarium at a reasonable price, then this Purewaterclub RO and DI portable system is absolutely the best device for you.

The system is effective in creating bacteria-free and chemical-less safe water for your fish tank hence I will always advise you to take the plunge.

View The Product Now

6. Aquatic Life RO Buddie Reverse Osmosis 50 Gallon 4 Stage System

While opting to buy an RO filter for your fish tank, do not underestimate the fact of having a multiple stage filter as for deep cleaning of your tap water, the number of stages matters a lot. This RO Buddie Reverse Osmosis filter from Aquatic life is available in 50 gallons 3 and 4 stage and 100 gallons 4 stage.

Aquatic Life RO Buddie Reverse Osmosis SystemsYou can have any of them according to your need but quality and efficiency are guaranteed with all of the three. The affordable pricing and easy to set up features are the main factors which govern the huge popularity of this filter among the users.


The features this filter includes are very advantageous if you compare them in terms of the price. Also, all of them are essential to have in order to get clear and purified water for you and your fish tank. The features are –

  • The small footprint of the reverse osmosis system makes it easier for you to place it under cabinets or in small places.
  • All the sediment, carbon and DI cartridges are up-front and effortless to replace.
  • The membrane housing accepts standard 11-3/4 in membrane filters.
  • The faucet adapter is incorporated in this package which makes it easy to connect to the standard male hose thread/bib.
  • The 4 stages used in this filter are Thin Film Composite or TFC membrane RO cartridges, Carbon, Sediment and mixed bed DI cartridges to effectively and efficiently remove substances that are harmful to your fish tank.
  • Total dimensions of the RO system are 13.8 x 7.5 x 6 inches.
  • This aquarium RO system from Aquatic life is only of 3.9 pounds.

Last Verdict:

As this filter of reverse osmosis for saltwater aquarium has an affordable pricing yet fulfills all the essential features to make the tap water safer for the aquatic lives, it is undoubtedly one of the best RO systems for aquariums to have.

View The Product Now

7. OPPM Portable 100GPD Reverse Osmosis RO+DI Filtration POQ-4B-100

The 4 stage Reverse Osmosis Reef water filter system has the capacity of filtering water up to 100 Gallons per day but to reach at least 50 gallons per day, the user must have 65 PSI incoming water pressure.

0PPM Portable 100GPD Reverse Osmosis RO+DI Filtration POQ-4B-100The best part of this filter is that it comes at a really affordable price and the weight of the RO filter helps you to carry it anywhere you want. You can also use this cheap reverse osmosis filter for the aquarium to filter drinking water but add one carbon filter after the DI stage, to get safer and pure water.

As having a Reverse Osmosis system is essential for your fishes to get clean water, you cannot deny the advantages of having a 4 stage RO and DI filter like this from Purewaterclub.


While buying best RO DI system from Purewaterclub, you get the best features in the industry at a reasonable rate. This 4 stage reef RO system has the below features –

  • The fastest portable pure water filter on the market.
  • The best and reliable TFC Reverse Osmosis membrane made in the U.S.A.
  • Equipped with advanced level technology to provide you with the greatest quality water that your aquarium deserve.
  • Very easy to install RO water system for aquarium so need of a plumber.
  • Best used as a countertop filter.
  • Stage – 1: Sediment Block which traps particles of 5 microns and larger.
  • Stage – 2: The carbon block filter for the adsorption of the Volatile Organic Compounds, chloride, sediment etc.
  • Stage – 3: The semipermeable membrane of 100 GPD allows small molecules only, like H20 to pass.
  • Stage – 4: Inline Deionization filter to trap salts.
  • It removes 99% of all sodium, lead, aluminum, copper,  mercury, arsenic, mercury, calcium etc.
  • The pre-filter will efficiently work for 6 – 12 months and the membrane will be active for 12 – 24 months.
  • However, you must consider changing the DI filter per 300 – 400 gallons to keep the performance up to the mark.
  • The total weight of the reverse osmosis water filter for the aquarium is 4 pounds.

Last Verdict:

The 4 stage Reef Reverse Osmosis for fish tank and DI filter of 100 GPD from Purewaterclub is a quality product which is packed with powerful features. The filter is made with the latest advanced technology so that it can provide with a more efficient filtration. Hence one of the best kits to keep your tank water safe for your fishes as well as to get pure drinking water for yourself.

I am very certain about the fact, that if you choose to buy this filter then, you will be taking the right decision towards keeping your aquatic live healthy.

View The Product Now

 Bottom Line:

Aquarium RO systems are one of the necessary units to have in possession for any aquarist as the efficiency of these filters cannot be denied due to the deep cleaning of the tap water to make it safe for the aquatic lives.

But before buying the best reverse osmosis system for aquariums, do not miss to read the reviews to choose the best-suited unit for you.