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Marlin 4 Stage Reverse Osmosis unit 100 gallons per day

Marlin 4 Stage Reverse Osmosis unit 100 gallons per day

Regular price $239.00
Regular price Sale price $239.00
Sale Sold out

SKU:SKU 4stw

If you are looking for an entry level Reverse Osmosis unit at the right price, then look no further!

4 Stage Reverse Osmosis unit 100 gallons per day

Standard 4 stage Reverse Osmosis Unit 

Now compare this to other units! Great Value! 


With this unit, however you are getting the real McCoy, at a fraction of its retail cost.



All ¼"push-connect fittings
Includes canister wrench and all installation adaptors and fittings



Replacement cartridge set for sale here 

Procuring pure water rests at the very baseline of success for the modern aquarist.  It rises to this challenge with the conception of the Deluxe  RO water filter. Through sound component selection and optimization of contaminant extraction, Deluxe  RO units minimize energy use, water consumption and media replacement.


  •  Reverse Osmosis models consist of RO and Post Treatment process when added together produce the finest complete water treatment system.   

This is the only proven way to take out the contaminants in your Town Water, Tank Water and Dam / Pond Water. For those that do not like Fluoride this is the only means of eliminating this additive in your Town Water.   


The stages are as follows (please refer to attached diagram):  

  1. Poly Sediment Filter - this filter is designed for purity, corrosion and chemical resistance, available at 10 micron. This removes sand, salt, dirt and rust particles.  
  2. Block Carbon Filter -  this filter is for the effective filtration of water for certain VOC’s (Volatile Organic Compounds (are organic chemical compounds that have high enough vapor pressures under normal conditions to significantly vaporize and enter the atmosphere. A wide range of carbon-based molecules, such as aldehydes, ketones, and other light hydrocarbons are VOCs), eg: chlorine taste and odor and sediment reduction down to 5 microns.
  3. Vontron 100gpd Reverse Osmosis Filter – This is for the RO desalting through and RO membrane. 


What is Reverse Osmosis?

Reverse osmosis (RO) is a separation process that uses pressure to force a solution through a membrane that retains the solute on one side and allows the pure solvent to pass to the other side. More formally, it is the process of forcing a solvent from a region of high solute concentration through a membrane to a region of low solute concentration by applying a pressure in excess of the osmotic pressure. This is the reverse of the normal osmosis process, which is the natural movement of solvent from an area of low solute concentration, through a membrane, to an area of high solute concentration when no external pressure is applied. The membrane here is semi permeable, meaning it allows the passage of solvent but not of solute.   

The membranes used for reverse osmosis have a dense barrier layer in the polymer matrix where most separation occurs. In most cases the membrane is designed to allow only water to pass through this dense layer while preventing the passage of solutes (such as salt ions). This process requires that a high pressure be exerted on the high concentration side of the membrane, usually 2–17 bar (30–250 psi) for fresh and brackish water, and 40–70 bar (600–1000 psi) for seawater, which has around 24 bar (350 psi) natural osmotic pressure which must be overcome.   

This process is best known for its use in desalination (removing the salt from sea water to get fresh water), but it has also been used to purify fresh water for medical, industrial and domestic applications since the early 1970s.   

When two solutions with different concentrations of a solute are mixed, the total amount of solutes in the two solutions will be equally distributed in the total amount of solvent from the two solutions.   

Instead of mixing the two solutions together, they can be put in two compartments where they are separated from each other by a semi permeable membrane. The semi permeable membrane does not allow the solutes to move from one compartment to the other, but allows the solvent to move. Since equilibrium cannot be achieved by the movement of solutes from the compartment with high solute concentration to the one with low solute concentration, it is instead achieved by the movement of the solvent from areas of low solute concentration to areas of high solute concentration. When the solvent moves away from low concentration areas, it causes these areas to become more concentrated. On the other side, when the solvent moves into areas of high concentration, solute concentration will decrease. This process is termed osmosis. The tendency for solvent to flow through the membrane can be expressed as "osmotic pressure", since it is analogous to flow caused by a pressure differential.   

In reverse osmosis, in a similar setup as that in osmosis, pressure is applied to the compartment with high concentration. In this case, there are two forces influencing the movement of water: the pressure caused by the difference in solute concentration between the two compartments (the osmotic pressure) and the externally applied pressure.  

Please refer to the Inorganic Contaminant Chart that is attached for what it does remove.  

Please also refer to the following explanations to this chart  

Cellulose triacetate   

The carbon pre-filter is omitted and cellulose triacetate membrane (CTA) is used. The CTA membrane is prone to rotting unless protected by the chlorinated water, while the TFC membrane is prone to breaking down under the influence of chlorine. In CTA systems, a carbon post-filter is needed to remove chlorine from the final product water.    

Thin Film Composites   

In the process of reverse osmosis, Thin film composite membranes (TFC or TFM) are used. Thin film composite membranes are semi permeable membranes manufactured principally for use in water purification or desalination systems. They also have use in chemical applications such as batteries and fuel cells. In essence, a TFC material is a molecular sieve constructed in the form of a film from two or more layered materials.  

Membranes used in reverse osmosis are, in general, made out of polyimide, chosen primarily for its permeability to water and relative impermeability to various dissolved impurities including salt ions and other small molecules that cannot be filtered. Another example of a semi permeable membrane is dialysis tubing

System includes:  


      Reverse Osmosis Unit  

      White Tubing  

     Accessories: Faucet Assembly, Piping Insert ¼” (5), Screws  




Daily Production: 380 litres (at 25 degrees Celsius)   


Temperature: 5 – 45 degrees Celsius   

Inlet Water TDS:  < 1000 ppm  

Main Rejection: 92 – 99%   

Stages: 4


Concerned about Fluoride?

Reverse Osmosis will remove 93.9% of Fluoride added to town water. Also these units have been certified, as indicated, for compliance to NSF standards for the REDUCTION (not complete elimination) of:

  • Arsenic V
  • Barium
  • Cadmium
  • Chloramine (monochloramine-aesthetic)
  • Chlordane
  • Chlroine (aesthetic)
  • Copper
  • Cysts (Giardia, Crytosporidium, Entamoeba, Toxoplasma)
  • Fluoride
  • Hexavalent Chromium
  • Lead
  • Mercury
  • MTBE (Methyl Tert Butyl Ether)
  • Nitrate/Nitrite
  • Particulate Matter, Class I (0.5 micron)
  • PCB (Polychlorinated Biphenyls)
  • Radium 226/228
  • Selenium
  • Total Dissolved Solids (TDS)
  • Trivalent Chromium
  • Toxaphene
  • Turbidity
  • Volatile Organic Chemicals Please be advised that R/O units are best installed either in a garage or a weather protected outside area as the risk of leakage could damage internal fixings. We are not responsible for any damage caused by leakage.
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