In fish farming, the need arises for to ‘detoxify’ the water from substances and elements that is detrimental to the health of the fishes. For this reason, working directly with tap or well water doesn’t just cut it. This is because experiments have shown that these kinds of water contain substances like nitrates, phosphates, chlorine, heavy metals, silicates and other elements that are not suitable for aquarium lives. This problem leads us to the concept called reverse osmosis.

Best Reverse Osmosis Review and Guide

Definition of Reverse Osmosis (Ro)

In natural processes, it is expected that the stronger of two forces usually wins and usurp the weaker force. This is seen in a process called osmosis. It is the movement of molecules of a solvent through a semi permeable membrane from a less concentrated solution into a more concentrated one.

Likewise, reverse osmosis is a process that aims to move molecules from a more concentrated solution to a less concentrated one by applying pressure on the later. This simply means that external pressure/forces are brought in so that the weaker of the forces wins. It is through this method that the elements and substances in tap or well water are purified and made wholesome for aquatic lives. The tap or well water is forced through a semi-permeable membrane under pressure, leaving behind contaminating and large particles so that only the cleanest water is collected.

Major Problem with RO Water

There is often a downside to everything good and reverse osmosis is no less. Because RO water is 99.9% clean, it is no longer hard or alkaline and all traces of elements – even those beneficial for microbial activities have been wiped out. And since all fishes need a degree of hardness and alkalinity to maintain PH levels in water, RO water would not suffice.

Two processes have been identified as a way to overcome this problem:

  • One involves mixing the RO water with a portion of tap water in a bid to put back some of the elements extracted from it. However, getting the right proportion is on a trial and error process; plus doing that defeats the initial process of reverse osmosis.
  • Another involves re-mineralizing. It involves adding essential salts and minerals into the RO water in the right proportion. They are re-mineralizing products available in the market with some already proportioned for use by specific fishes. The fish keeper can personally apply the product in mix proportions as directed by the manufacturers.

Whichever method works for you, the goal is to create suitable water condition for habitation by our precious fishes.

Review of Some Best Reverse Osmosis Systems – Consumer Reports

If you decide not to buy RO water but instead prepare yours, a review of some of the units available would give you an idea of the most suitable for your need. This section of the article covers it:

1. Aquatic Life RO Buddie Reverse Osmosis System

Aquatic Life RO Buddie Reverse Osmosis System


The Aquatic Life RO Buddie 3-Stage Reverse Osmosis (RO) system provides economical filtered water. It features unbelievable affordability and functionality in a very compact, easy to install and mount design. It is built with a Thin-Film Composite (TFC) Membrane in conjunction with Carbon and Sediment pre-filter cartridges to effectively and efficiently remove harmful substances such as heavy metals, total dissolved solids, Chlorine and particulate matter from tap water. The sediment and carbon pre-filter cartridges are upfront and easy to replace also.

Product features:

  • Gallon per day (GPD):
  • Filtration stages: 3 – Thin-Film Composite (TFC) Membranes; Carbon and Sediment pre-filter cartridges.
  • Product dimension: 7.2 x 4 x 13.8 inches.
  • Prize: $44.27.
  • Accompanying kit: Cartridges, Membrane, Faucet Adapter, Membrane Wrench, mounting brackets.
  • Water tank: Available (2.8 gallon tank) bought separately.
  • Warranty: Limited.
  • Customers complained that it didn’t live up to the 50gpd as it claims
  • Customers complained about slowness in water output
  • They are also complains of leakages
  • Complains about instruction on setup not clear enough


2. APEC 5-Stage Ultra Safe Reverse Osmosis Drinking Water Filter System


APEC 5-Stage Ultra Safe Reverse Osmosis Drinking Water Filter System

The ROES-50 reverse osmosis device delivers high quality clean, filtered drinking water at an affordable price. It is guaranteed to remove up to 99% of all contaminants like chlorine, taste, odor, toxic fluoride, arsenic, lead, and chromium. The 5 stage filtration method will provide users with high quality water for drinking and fish keeping purposes. There is a Free Life Time Loyalty Support Service on the product, a true Leak-Free Fittings Protection and Super-Efficient APEC Carbon Blocks for optimal performance.

Product features:

  • Gallon per day (GPD): Not specified.
  • Filtration stages: 5.
  • Product dimension: 16 x 5.2 x 17.5 inches; 25 pounds.
  • Prize: $199.99.
  • Accompanying kit: Lead-Free chrome faucet, FDA Certified JG Food grade tubing.
  • Warranty: One year limited warranty.
  • They are minor complains about the unit not shutting off when the tank is full.
  • Complaints about leakages.
  • Complains on wastage of water through drain after tank fills.


3. Express 5 Stage Undersink Osmosis Drinking Filtration System


 Express 5 Stage Undersink Osmosis Drinking Filtration System

This is an under counter purifier for 100% clean drinking water through a five stage purification process. It boasts of a high quality Quick Connect fittings that replace threaded or flanged connections, which require wrenches. Each product is shipped with simple, easy-to-follow instructions and technical support is provided by the manufacturer.

Product features:

  • Gallon per day (GPD): Not specified.
  • Filtration stages: 5 micron Melt-Blown polypropylene sediment, Gac activated carbon filters, 5 micron carbon filters, thin film 50 GPD RO membrane and : inline granular carbon filter.
  • Product dimension: 18.2 x 19 x 16 inches.
  • Prize: $169.98.
  • Accompanying kit: NSF Certified storage, Plastic System and Brass Faucet.
  • Warranty: One year limited warranty, Lifetime support from Express Water.
  • The instruction manual is not so detailed.
  • They were also complaint of leakages.
  • Water production is comparably slow.


4. Reverse Osmosis Water Filter System

Reverse Osmosis Water Filter System


This is a fairly inexpensive RO system sold by Mims trading. It provides pure home filtered water through two pre-filter stages. The first removes sediments, rust, dirt and solid debris while the second carbon filter removes chlorine, odor, dissolved salts metals etc. and protects the RO membrane. The post-filter stage which is final removes tastes and organic chemicals. It also has a storage tank that holds the filtered water until needed.

Product features:

  • Gallon per day (GPD): Not specified.
  • Filtration stages: 2: sediment and carbon pre-filters.
  • Product dimension:9 x 16.4 x 14.1 inches; 20.5 pounds.
  • Prize: $115.25.
  • Accompanying kit: None specified.
  • Warranty: Not available.
  • Consumers complained that the Filtering is very slow.
  • Customers complained that the directions for installation are a bit confusing
  • Customers also complained of product arriving with broken parts.


5. Portable Aquarium-Countertop Reverse Osmosis: 4 Stage System Membrane

Portable Aquarium-Countertop Reverse Osmosis Water Filter System-DI/ RO : 4 Stage System Membrane


This is a portable installation-free RO system for use in aquarium, laboratory, or at home for drinking water purposes. It uses 4 stage filtration processes to provide ultra-pure water for every use.

Product features:

  • Gallon per day (GPD):
  • Filtration stages: 4: inline sediment filter, inline carbon filter, reverse osmosis membrane, inline DI resin cartridge.
  • Product dimension: 18.9 x 16.4 x 14.1 inches; 20.5 pounds
  • Prize: $115.25
  • Accompanying kit: Faucet adapter, with all necessary tubing & connections
  • Warranty: Contact seller (LiquaGen).
  • Slow rate of water filtration and output.
  • It also makes a lot of waste water.


The RO systems reviewed above can both be used for filtering drinking water and preparing fresh water for aquariums. Some of the brands boast of up to 5 filtration method while other are less. Hopefully, it helps you to make an informed purchase.

Also, Discover the Best Protein Skimmers for Your Aquarium Here.