Frequently Asked Questions

What is pH?

The term pH stands for “potential for hydrogen.” It’s a measure of the concentration of hydrogen ions in a diluted solution. Acidic solutions contain more hydrogen ions, while alkaline solutions contain fewer. It is measured in the field to determine if water has the potential to be corrosive or form scale.

What is Silt Density Index (SDI)?

Nearly all feed water contains varying levels of suspended solids, from sources such as bacteria, iron, clay, clarification chemicals and other colloidal or particulate matter. Under certain conditions, the presence of these materials can result in membrane fouling characterized by decreased permeate flux, increased operational pressure, and/or reduced salt rejection. Silt Density Index (SDI) is a simple field test used to predict the degree of membrane fouling and expected frequency of cleaning when operating a reverse osmosis unit on a particular water supply.

How do you select the right water softener?

Choosing the right water softener begins with testing the hardness of your water, which varies widely by region. Once hardness is determined, it’s important to consider the size of softener required. Size is based on your volume needs and can be measured by daily use or peak demand. The last consideration involves the type of sophistication desired (manual, metered or timed) and if it will be operating with other equipment such as a reverse osmosis unit.

What is fouling?

Fouling occurs when material passing through a reverse osmosis system becomes caught in the membrane, resulting in decreased performance. Fouling may be organic or inorganic, and each type presents different challenges to the integrity of the water system. A simple pretreatment can often reduce or remove incidents of fouling. Ultrapure offers both chemical and mechanical pretreatment solutions to be used with a reverse osmosis system.

What are the laboratory grades of water?

Different levels of quality are required for a vast range of applications, therefore different grades of water must be purified and utilized to match the required procedures.

• Type I: Type I is considered ultrapure water. The most common applications for this grade include high performance liquid chromatography (HPLC), gas chromatography, immunocytochemistry, cell culturing and tissue culturing.
• Type II: In short, Type II water is more pure than Type III water but not ultrapure like Type I. Type II water is most typically used as feed to instruments, clinical analyzers and Type I systems. Additional applications include electrochemistry, sample dilution, media preparation and radioimmunoassay.
• Type III: Less pure than Types I and II, Type III water removes between 90 and 99 percent of contaminants. It is produced using reverse osmosis and the starting point for many laboratory applications, such as washing machines, dishwashers and autoclaves. Type II water is additionally used as feed to ultrapure Type I systems.

What is source water?

Source water provides water for public drinking water supplies and private water wells. It can include surface water, like streams, rivers and lakes, or ground water which comes from aquifers.