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Understanding Lab Water Systems: A Comprehensive Guide to Deionization

by Matt Miller July 06, 2024 0 Comments

Understanding Lab Water Systems: A Comprehensive Guide to Water Purity Levels and System Selection

With over 30 years of experience in the water treatment industry, I've seen firsthand the crucial role lab water systems play in ensuring accurate and reliable results in various scientific fields. From ultra-pure Type 1 water needed for molecular biology to Type 3 water for general laboratory use, the purity levels must meet stringent standards.

Lab water quality comes in different levels. From ultra-pure Type 1 water, needed for detailed molecular work and analytical tests, to Type 3 water for general uses, each type is designed to meet specific lab needs. This classification isn't random; it's carefully planned to match water purity with the requirements of various scientific tasks.

Types of Water

The American Society for Testing and Materials (ASTM) classifies water used in laboratory settings into four grades: Type I, Type II, Type III, and Type IV. While these ASTM classifications are widely recognized, other important standards for water purity include ISO and CLSI-CLRW. In this article, we will refer to the ASTM designations when discussing the types of water used in laboratory work.


Type 1 (Ultra-Pure) Water

Type 1 water is the highest purity level, making it ideal for critical lab applications. It's essential for tasks like molecular biology, cell culture, and analytical techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry. Type 1 water must meet the following parameters:

  • Resistivity: Greater than 18 MΩ-cm
  • Conductivity: Less than 0.056 µS/cm
  • Total organic carbons: Less than 50 ppb

Type 2 Pure Water

Type 2 water has a lower purity than Type 1 and is typically used for general laboratory tasks. These include preparing buffers and media, rinsing glassware, and certain analytical techniques where high purity isn't as critical. It can also be used as a feedwater to clinical analyzers. Many times Type 2 water is used as a feed water for Type 1 water production.

Type 3 Water (RO Water)

Type III grade water, commonly referred to as RO water, is produced using the advanced purification technology of reverse osmosis. Among the various types of pure water, Type III possesses the least purity level, making it the ideal choice for fundamental laboratory applications. These include cleaning glassware, preparing heating baths, and media preparation. Additionally, it serves as an essential feed water for producing higher purity Type I water, vital for more sensitive laboratory processes.

Which System is right for my lab?

Once you have determined the water quality you need, other factors to consider in deciding the system for you (a) upfront cost, (b) serviceability, and (c) cost of ownership over the life of the system.

Upfront Costs

When considering the upfront costs of lab water purification systems, it's crucial to understand that these costs can vary significantly depending on the vendor and the specific purity levels required for your laboratory applications. The market offers a wide array of vendors, each with different technologies and pricing strategies. Generally, the price of a water purification system is closely linked to the type of water purity it is designed to achieve. For instance, systems that produce Type 1 Water, also known as Ultrapure Lab Water or Reagent Grade Water, are typically at the higher end of the price spectrum due to the stringent purity requirements they meet, including those specified by CLSI Type 1 and ASTM Type 1 standards.

Specifically, systems like Milli-Q Water systems are renowned for providing high-purity 18 Meg Water or DI Water, which is essential for critical scientific applications such as chromatography, mass spectrometry, and molecular biology. The higher the required purity and the more contaminants that need to be removed, the more complex and costly the system tends to be. This is due to the advanced filtration technologies employed, such as ion exchange, UV treatment, and submicron filtration, which are necessary to achieve the low levels of organic, inorganic, and bacterial contaminants required in these high-purity environments. Therefore, while the initial investment in a high-grade water purification system may be substantial, the accuracy and reliability of experimental results it enables can justify the cost.


The serviceability of lab water purification systems is a crucial aspect that varies significantly between models and manufacturers. Some high-end systems, particularly those designed to produce Type 1 Water or Ultrapure Lab Water, often incorporate complex technologies that require specialized knowledge for maintenance and repairs. Such systems, including those that produce Milli-Q Water or meet stringent CLSI Type 1 and ASTM Type 1 standards, typically necessitate service by trained factory representatives. This specialized service can be quite costly, with rates often exceeding $300 per hour, not including additional travel expenses from locations potentially hours away. The complexity of these systems ensures optimal purity levels like 18 Meg Water or DI Water, but it also means that routine service can become a significant ongoing expense.

Conversely, some manufacturers have recognized the value of simplicity and user-friendliness in the design of their water purification systems. These systems are engineered with the end user in mind, making regular maintenance tasks straightforward enough to be handled in-house. Many of these user-friendly systems come with detailed do-it-yourself videos and easy-to-follow manuals online, empowering users to perform regular upkeep and minor repairs without the need for expensive specialist intervention. This approach not only reduces the total cost of ownership but also increases the system’s uptime, as users do not have to wait for external service technicians. By designing systems that facilitate easy access to filters and other components, manufacturers enable laboratories to maintain consistent water quality, such as Reagent Grade Water or DI Water, without the hefty service fees associated with more complex systems.


Cost of Ownership

The cost of ownership for lab water purification systems can vary significantly among different manufacturers, largely due to the ongoing need for consumables. All lab water systems, whether designed to produce Type 1 Water, Milli-Q Water, or Ultrapure Lab Water, require regular replacement of key components to maintain their high levels of purity. Consumables such as Polishing Cartridges, final 0.2-micron filters, Ultrafilters, UV bulbs, and Sanitization Packs are essential to ensuring the system continues to meet the stringent requirements of CLSI Type 1, ASTM Type 1, Reagent Grade Water, and 18 Meg Water.

The price of these consumables can vary greatly from one manufacturer to another, impacting the overall cost of ownership. For example, some manufacturers might offer lower initial costs for their systems but have higher prices for replacement parts. Conversely, other manufacturers might have higher upfront costs but offer more affordable consumables. Over the lifespan of a lab water system, these differences can add up to significant savings. In many cases, laboratories can save well over $1,000 annually on consumables alone by choosing a system with more cost-effective replacement parts.

Additionally, the frequency with which these consumables need to be replaced can also affect the total cost of ownership. Systems that require less frequent replacements or use more durable components can further reduce annual operating costs. When evaluating different lab water systems, it's essential to consider not only the initial purchase price but also the long-term expenses associated with maintaining the system. By factoring in the costs of consumables like Polishing Cartridges, UV bulbs, and other critical components, laboratories can make more informed decisions that optimize both performance and budget, ensuring a reliable supply of DI Water or Reagent Grade Water without unnecessary financial strain.

Another factor in cost of ownership is the type of feedwater you are starting with. Feeding lab water purification systems with high-quality RO water can significantly reduce the cost associated with DI Polishing Filters and other consumables. When a system is supplied with RO water that has already undergone an initial purification stage, the burden on DI Polishing Filters to remove impurities is greatly minimized. This pre-treatment step ensures that a majority of the contaminants have already been filtered out, thereby extending the lifespan of the DI Polishing Filters. As a result, the frequency and cost of replacing these filters are reduced. This is particularly important for systems producing Type 1 Water, Milli-Q Water, and other high-purity waters like Reagent Grade Water or 18 Meg Water, where maintaining ultra-low levels of impurities is critical. By incorporating high-quality RO water as a feed, laboratories can achieve substantial savings on consumables, making the overall operation of the water purification system more efficient and cost-effective.


In summary, selecting the right lab water system requires careful consideration of water purity levels, system costs, and maintenance needs. By choosing the appropriate system, laboratories can ensure the reliability and accuracy of their results. Contact us today to learn more about our lab water purification solutions

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