Water Treatment Lab

RO plant with Deionizer

Water Treatment Lab (WTL) offer best RO price for Reverse Osmosis (RO) and Deionizer Plant for labs, Pharmaceutical, Neutraceutical etc. RO and DI filters use different physical reactions to clean water. Reverse Osmosis (RO) is used to partially clean-up tap water to make it roughly 90% to 99% pure. Deionization (DI) filters exchange positive hydrogen and negative hydroxyl molecules for positive and negative contaminant molecules in water. DI filtering and other processes are sometimes referred to as “water polishing.”

Understanding the difference between reverse osmosis (RO) and deionized (DI) is important when identifying the right water purification unit for your lab and Pharmaceutical. Having access to high quality water is essential for laboratories to carry out their daily processes and workflows. By taking a closer look at different methods of producing both types of water, RO and DI, you can feel confident in your decision regarding water purification systems. 


Reverse Osmosis Water

RO grade water is quite simply the reverse of the naturally occurring process of osmosis.  Osmosis is the movement of water molecules from low ion concentration to high ion concentration through a semipermeable membrane. For example, the osmotic process is used by our cells to maintain osmotic balance of the intercellular environment. The method of producing RO water is a simple matter of applying increased pressure to one side of the system. By applying additional pressure to one side, in the case the untreated or dirtier water side, feed water is forced through semipermeable membranes resulting in more purified water.  The RO process can typically remove 90-99% of contaminants. RO purification is a cost-effective method because if used properly RO membranes can last for years.

Deionized Water

DI grade water, or Type II water, is purified water that has almost all its mineral ions removed, such as cations like sodium, calcium, iron, and copper, and anions like chloride and sulfate. The DI process leverages specially manufactured ion-exchange resins that exchange hydrogen (H+) and hydroxyl (OH-) ions for dissolved minerals, and then recombine to form water (H2O). Over time, positively and negatively charged contaminants in the water displace all the active H+ and OH- molecules on the DI resin and at that time the filter must be replaced. Another benefit of the DI purification process is that it is an on-demand process for supplying DI or Type II when needed. Because the ion-exchange resin in not a physical filter with a pore size bacteria and dissolved organics will not be captures, so knowing production water requirements is essential when selecting a water purification unit. 

There are several ways to establish the quality level of purified water by using different filtrations methods. The simplest test is a direct measurement of electrical conductivity or resistivity. Most dissolved inorganics are either positively or negatively charged and can transmit an electrical current when electrodes are inserted in the water. The more ions that are present, the greater the conductivity, or the lower the resistivity of the water sample. Conductivity is expressed in µS/cm (micro Siemens/cm) and is used to measure water with many ions present.  

Applications of Deionizer (DI) Water

In addition to medical product manufacturing, DI water is used today in facilities across various industries, required for a myriad of reasons.

For example, a glass manufacturer may require DI water to rinse their product after it’s complete. Using tap water would result in TDS deposits (calcium, magnesium, silica) on the glass surface.

For the biotech and pharmaceutical industries, bacteria-free water is an absolute necessity. That’s because if there is any chance that a solution or the chemical mixture could end up in a patient’s body, any amount of organic content could be of great harm.

In specimen processing where surgical instruments are cleaned, deionized water is used in conjunction with a liquid or gas disinfectant and a microbial-free rinse to ensure that the instruments are free of any residuals, thereby ensuring absolute sterility. This is something that the use of tap water cannot guarantee.

Deionized water has had almost all of its mineral ions removed, resulting in bacteria-free purified water.

For many industries, like the medical and pharmaceutical industries, deionized water is the thing that helps maintain product safety and integrity.


  • Increase life of machinery use in industry by avoiding buildup salt layers on machinery
  • Deionizer water can be to lubricate and cool machinery
  • It reduce TDS of your water up to 0 which is very useful for manufacturing of Pharmaceutical products, lab tests etc.
  • It can you use in titration

Frequent Asked Questions about Deionizer Water

Q- What is Deionizer water?
A: Deionizer (DI) water or Demineralize water simply means that either a net negative or positive charge and have 0 TDS.
Q- How long does water stay deionized?
A: Although DI water is pure, its life is not more than 2 years. This is because the container used to store DI water releases metals or synthetic nutrients over time.
Q- What is difference between RO and DI water?
A: Reverse Osmosis (RO) water is partially cleanup up to 90-99% and have some salts in it or TDS around less than 100 but Deionizer (DI) Water 100% free from any anion or cation present in water and have TDS Zero reading.