Scale: The Biggest Problem in the Laboratory Equipment Performance

Scale build-up is not typically at the top of our minds when considering threats to laboratory operations. Issues like power outages, software failures, or contamination are generally more concerning. However, one of the most common and expensive lab culprits is quite mundane: scale. 

Scale is a hard, chalky deposit formed by minerals that are present in water. It insidiously works behind the scenes, steadily diminishing efficiency, fouling critical equipment and driving up running costs. Unchecked, scale will shorten equipment lifetime, degrade results, and even cause unplanned downtime. 

In short, it’s the silent killer of any lab that uses laboratory water purification systems. 

What is scale and why does it form? 

Scale is mainly composed of calcium carbonate, magnesium hydroxide and other mineral salts. It is formed when “hard” water (water with a high concentration of dissolved minerals) is heated, pressurised or concentrated. 

Scale can commonly occur in laboratories in:  

• Autoclaves and sterilisers  

• Glassware washers and dishwashers  

• Reverse osmosis (RO) water systems  

• Water baths, boilers and steam generators 

Scale forms when water is heated or experiences a pressure change and minerals precipitate or come out of the solution and coat a surface. Layers build over time, and even moderate hardness can lead to scale deposits in thin, yet destructive, layers. 

Why scale is a big problem for laboratories 

Scale is a nuisance in the manufacturing or food service industry. In the laboratory it is more serious issue as it directly impacts lab results and experiments. Here’s how: 

1. Lowered heating efficiency  

Scale accumulation creates an insulating layer on the heating components of equipment such as sterilisers and water baths. This:  

• Slows down heating times  

• Makes heaters work harder  

• Increases energy use  

• Accelerates wear on components  

• Energy bill cost reduction – 1 mm of scale build-up can reduce heating efficiency by as much as 10%. That’s more on your energy bill. 

2. Shorter equipment lifespan 

Scale has a significant impact on equipment and its parts in various ways: 

• In RO systems, scale blocks the membrane pores and causes the pressure and product flows to drop 

• In sterilisers, it causes overheating of the system and accelerates gasket failure; 

• In washer, it blocks the spray arms and nozzles, which often result in incomplete wash cycles; 

The consequence? Increase in equipment repairs and frequent replacement. 

3. Water purity risks 

In laboratories that use reverse osmosis for water purification, scale deposits on membranes cause increased pressure drops and lower product flows. This can: 

• Cause contamination of sensitive experiments  

• Violate purity requirements (ASTM, CLSI) 

• Cause problems with water supply and demand  

• Cause an increased need for expensive membrane cleaning/replacement 

4. Higher hidden costs 

In addition to repairs and replacements, scale can increase operational costs through: 

• Increased chemical cleaning  

• Frequent maintenance visits  

• Energy inefficiency  

• Unplanned downtime  

These can cost many times more than effective prevention. 

The stealth factor: Why scale goes unnoticed 

Scale’s most insidious quality is that you often don’t see it… until it’s too late. In the beginning: 

• Autoclaves pass validation tests, despite a coating of scale. 

• RO units make acceptable quality water, even as membrane efficiency and flow rate is reduced. 

Because it’s a gradual reduction in performance, it’s easy to ignore… until a failure takes the unit completely offline. 

How to stop scale before it starts 

The best way to combat scale is to avoid it completely. In the laboratory, this typically involves a dual approach of water treatment and preventative maintenance. 

1. Test your water routinely  

Hardness levels can fluctuate seasonally and by source with municipal supplies. Routinely test for hardness, alkalinity, and TDS to make sure you know your risk profile. 

2. Install TAC (Template Assisted Crystallisation) or conventional softener water treatment 

TAC functions by changing the crystal structure of the hardness mineral, causing them to repel from surfaces to allow harmful calcium and magnesium modules to be rinsed easily to drain. 

Conventional Water Softening functions by using a bed of charged media to exchange the hardness ions (calcium and magnesium) for harmless soft sodium ions  

Either system can be very effective when installed before an RO unit, or other lab process equipment. 

3. Install reverse osmosis systems up front of equipment prone to scale issues (washers, Autoclaves, environment chambers etc.) 

Reverse osmosis systems designed to feed good quality water to equipment such as washes/autoclaves etc. will ensure the water being used by the equipment is of good quality and has no calcium/magnesium ions present 

Purite Descale 160 is designed to feed vulnerable equipment with water of good quality and low hardness 

3. Protect your RO membrane 

TAC systems or water softeners in front of your reverse osmosis system will prevent scale from accumulating on the membrane surface. This helps maintain water purity and maximises membrane life. 

TAC systems are particularly effective and suited to laboratory RO systems 

4. Schedule flushing and cleaning 

Many modern RO units include automatic membrane flushing, which rinses away concentrated minerals before they precipitate into scale. 

5. Train staff to spot warning signs 

Longer heating cycles, reduced flow rates, or patchy cleaning are all early indicators of scale build-up. 

The benefits of scale prevention 

By addressing scale proactively, laboratories can expect: 

• Reliable performance for validated processes 

• Lower operating costs thanks to energy efficiency and fewer repairs 

• Extended equipment life with fewer major breakdowns 

• Consistent compliance with regulatory water purity standards 

In a laboratory setting, these benefits aren’t just about money—they’re about protecting research integrity, operational continuity, and patient or product safety. 

Scale is a dangerous, invisible, and often silent saboteur in the lab. In settings where accuracy and precision are the norms, scale can cause havoc, unpredictable downtime, expensive repairs, and ruined results. However, if you know about how scale forms, how to recognise its early indicators, and how to prevent scale in the laboratory, you can protect your equipment and optimise its performance for years to come.  

TAC pre-treatment, water softening or Purite Descale 160 Eco – Your lab’s next step 

Adding TAC pre-treatment, water softeners or the Purite Descale 160 ECO, an efficient, reliable and intelligent RO pretreatment system, means you have powerful tools on your side in the fight against scale. Preserve accuracy, reduce energy consumption and safeguard expensive equipment while remaining one step ahead of maintenance issues. 

Bid farewell to scale. Say hello to smarter, cleaner lab operations with Purite. Contact us and discover more about how TAC, water softeners or Purite Descale 160 Eco can contribute to the improvement of your laboratory water purification processes.