Water Specifications for Memmert Equipment
Specs for the Following Units: HCP, HPPeco, ICH, ICO, CTC & WTB
What water do we use in our Memmert Climate Chamber or Water Bath?” is a common question we receive from our customers, that requires a complex answer of sorts. The Memmert Constant Climate Chambers and Water Baths currently require water with a conductivity of 5 – 10 µS/cm and a pH of 5.0 –7.0. This specific range is all about protecting the humidification system as well as the chamber or bowl from corrosion as well as calcification, and cleanliness regarding algae or bacteria build in up in the silicone hoses. The water required can be difficult to source, and expensive if purchased in small quantities. Let’s discuss some common water types, their Pro’s and Con’s (if any), and how to create the required water utilizing two different water sources.
Can I Use Tap Water?
Using tap water from a faucet can contain a large amount of chlorine and calcium carbonates. Chlorine is extremely aggressive under certain conditions and can create rust very quickly even on stainless steel components. Calcium carbonate and other dissolved solids can accumulate and solidify inside the steam generator, blocking the flow of water through and destroying the steam generator or calcium deposits in the bath that can be difficult to remove. These repairs can be costly, and lead to unnecessary downtime. Using demineralized, while free of calcium carbonate and other dissolved solids, still contains chlorine and can foster the growth of algae in the tank and silicone lines.
What about Distilled Water?
Distilled water is significantly cleaner than demineralized water but requires a greater effort to produce it. Distilled water is practically free of salts (chlorine), dissolved solids (calcium carbonate), and organic matter. While distilled water is less likely to deposit material in or on components, due to it being ultra-pure water, it can strip ions from metal components resulting in corrosion or pitting. As you can see, none of these water types are ideal.
Using a Conductivity Meter:
So how do we get to a happy point between dirty, high conductive water and clean, ultra-pure water? This can be done by using a mixture of small part tap water and large part distilled water. An accurate and calibrated conductivity meter (Extech EC150 used below) is required for this procedure. When small amounts of tap water are added to distilled water, there is a small increase in conductivity. As you will see in the below pictures, utilizing just a few milliliters of tap water with a high conductivity level added into 100 milliliters of ultra-pure distilled water you are able to create a water right in the required zone of 5 – 10 µS/cm.
By simple small additions of tap water into distilled water with thorough mixing, you can create and accurately measure to confirm you are using water that will not void your Memmert Climate Chambers or Water Baths warranty, nor damage any components of the interior of the chamber or bath itself. Using this method is inexpensive and easier than trying to source a laboratory grade water and can be done safely at your facility. Any questions, please let us know!