Before You Purchase an Industrial RO System: Pre-Treatment

If you’re looking to purchase an Industrial Reverse Osmosis (RO) System, there are quite a few things you need to think through.  At Complete Water Solutions, our goal is to come alongside you as a partner and help you make the best decisions for your business when it comes to your RO system.
After you’ve worked through feed water testing and sizing your RO system, the next step is pre-treatment. This step is very important and sometimes missed. For the purpose of this article, pre-treatment will be classified as the equipment required before the RO system is installed. 

history of water softeners, ion exchange softener, commercial softener

With no pre-treatment in front of your RO system, there will likely be one of two major issues. One could be major fouling, resulting in damage or excessive cleaning. If your water source is chlorinated, failing to pre-treat would likely result in damage to the membranes, unless they happen to be cellulose acetate.
We have seen membranes destroyed because of not using the correct or not using pre-treatment at all. The typical life of the RO membrane with proper pre-treatment and maintenance schedule can be anyway from 3-5 years. However, they’re expensive. We’ve seen a client spend over $30,000 a year on membranes simply because they weren’t using any pre-treatment (prior to working with Complete Water Solutions).
Below is a list of things to be aware of when it comes to pre-treatment and filtration.


Chlorine, also known as sodium hypochlorite and commonly known as bleach can be used in many different applications. Since the early 1900s, chlorine has been commonly used to disinfect municipal water supplies. Concerns over disease-causing microbes (pathogens), such as typhoid, dysentery, and cholera prompted the use of water treatment equipment and chemicals to help with disinfection. However, this can cause problems for your industrial RO system. Most RO Membranes in today’s market are Polyamide (PA) / Thin Film Composite (TFC) and do not have a high tolerance to chlorine. While most membrane manufacturers limit the amount of Free Chlorine that membranes can tolerate chlorine before degradation begins, there are some membranes in the marketplace that can tolerate chlorine. For the majority of RO applications, Chlorine removal will need to take place.

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There are a few options for free chlorine removal. One common way to remove chlorine from the feed water source is using carbon filtration prior to the reverse osmosis system. Sodium Metabisulfite is a chemical that is used in the process to remove total and free chlorine from the water source. You can read more about these processes in our full ebook.

UV System

A UV system is not a common way to break down chlorine but we at Complete Water Solutions have used it as such. Using UV over carbon or chemical offers benefits, like no backwashing Waste Water, and also offers disinfection. UV systems have to be sized properly 10-30 times the normal disinfection rate. There are some additional factors to take into consideration, such as inlet water quality, and you may need additional treatment before the UV System or you may experience higher operating costs. We can help you with that.

Hardness: Calcium, Magnesium, & Iron

Finally, Calcium & Magnesium is commonly known in the water industry as “Water Hardness”. Hardness is the measurement of calcium and magnesium minerals in the water source. Water hardness will directly impact
the performance of your RO System, not to mention if not treated it can lead to irreversible damage. There are many ways to handle hardness. Two of the most common options are water softening and chemical treatment. The last of the filtration steps to discuss is iron removal. Iron can be removed in a variety of ways from oxidation and precipitation, to ion exchange. The experts at Complete Water Solutions can help you find the best process to remove hardness and iron from your water.

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Trust CWS When It’s Time to Purchase an RO System

Working with Complete Water Solutions creates a partnership. We want to be there with you for the entire lifecycles of your Industrial Reverse Osmosis system. This sizeable investment is a major part of your production process and it’s something that should always be properly maintained and never left to chance. This is our area of expertise.  We’d be happy to help you throughout the process including the purchase and setting up a maintenance plan.
Contact us today to set up a time and date for us to come out and discuss your Industrial RO System needs.

About The Author

Nathan Olszak
28 Year Of Water Treatment Equipment Experience. I have been blessed with the opportunity to learn from the ground up. Starting in the water treatment field as a service technician. Servicing all major brands of water treatment equipment. Give Us A Call (855) 787-4200 or Email

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