Frequently Asked Questions

What is Automated Water Treatment?

Automated Water Treatment refers to the use of an automatic controller with electronic sensors to monitor the water condition and maintain it clean and safe at all times.


What is Integrated Water Treatment?

Integrated Water Treatment is a patented technology developed by CHEMTROL® that includes automatic control of all the different chemical and physical processes involved in water treatment. This includes Chemical Automation for the control of pH and sanitizer concentration, heater control, water balance with control of Total Dissolved Solids (TDS) and Langelier Index and automated filter backwash.

Only CHEMTROL® offers fully integrated, operator-friendly controllers that can perform all these operations simultaneously and safely.


What is Remote Operation?

Remote monitoring allows the operator to connect to a CHEMTROL® Programmable Controllers from a remote computer using the user-friendly web-server or via CHEMCOM® software program for Windows. Once connected, the operator can see the controller screen and perform all operations as if he was standing on the site of the facility.


What is True Duplex Remote Operation?

With the CHEMTROL® remote monitoring for Programmable controllers, the operator sees an exact replicate of the controller screen, not a simulation like other less advanced controllers. This makes it possible to perform all operations of the controller as if on site.


What is Chemical Automation?

Chemical Automation applies to the control of the sanitizer (chlorine or bromine) and of pH with the addition of acid or base. CHEMTROL® offers several programmable or analog controllers for chemical automation only.


Please explain pH?

pH is a logarithmic scale ranging from 0 to 14 developed by chemists to define the acidity of water. Water dissociates into two types of ions: hydrogen ions H+ and Hydroxyl ions OH-. An acid condition is caused by a predominance of hydrogen ions in water. An alkaline or basic condition is caused by the predominance of hydroxyl ions. Neutral water has equal concentrations of both and has a pH of 7.0. The recommended pH range for water treatment is generally from 7.4 to 7.6, that is slightly alkaline.


Why must I keep the pH above 7.4 ?

It is important to maintain the pH above 7.4 to prevent metal corrosion, staining and etching of plaster, damage to vinyl liners, eye irritation and loss of sanitizer.


Why must I keep the pH below 7.6 ?

It is important to maintain the pH below 7.6 to prevent water cloudiness, scale formation, eye irritation and loss of sanitizer efficiency (low ORP).


How do I increase the pH?

The pH is increased by adding soda ash, caustic soda or basic (alkaline) chemicals sold under trade names such as pH PLUS or pH UP. Be careful not to spill and rinse off any spill with large amounts of water.


How do I lower the pH ?

The pH is decreased by adding liquid muriatic (hydrochloric) acid, carbonic acid in gas form or dry acid sold under trade names such as pH MINUS or pH DOWN. Use only small amounts and do not spill.


How is sanitizer controlled?

The sanitizer concentration in water is monitored through its Oxidation-Reduction Potential with an ORP electrode. ORP (or Redox) represents the oxidizing power of the sanitizer which is closely related to its ability to disinfect water.


What is ORP?

ORP – which is measured in millivolts (mV) – provides a superior index of bacteriological water quality because it monitors the activity of the sanitizer rather than just its relative concentration as with conventional PPM (parts per million) test kits.

In 1972, the WORLD HEALTH ORGANIZATION (WHO) adopted 650 mV as the minimum ORP standard for disinfection of drinking water. An ORP level of 750 mV is recommended for public pools and spas.


Why do we need 650 mV as min for ORP ?

Numerous scientific studies have shown that this is the minimum required to prevent germs and bacteria. If you maintain this minimum, you should therefore automatically meet health department standards.


How many PPM of chlorine is 650 mV ?

This is difficult to answer as many chemicals in the water affect the activity of the chlorine and therefore its ORP. In pure water at a pH of 7.5 and without cyanuric acid, 650 mV of ORP corresponds to about 0.5 ppm of chlorine. In actual pool or spa water, it usually takes at least 1 to 2 ppm of chlorine to generate the same ORP.


Will an ORP of 650 mV stop algae ?

Unfortunately not, because algae are living organisms that adapt genetically to a constant level of sanitizer. You should therefore use an algicide if needed.


What affects ORP ?

A high pH, high cyanuric acid level or high TDS (Total Dissolved Solids) affect the activity of the sanitizer and therefore reduce its ORP.


Why do I get a low ORP ?

This may show either a low sanitizer level, or a pH above 7.6, or a cyanuric acid level above 100 to 200 ppm or a TDS above 2,000 to 3,000 ppm. If none of the above, it may be due to a defective ORP sensor.


How do I test the sensors ?

You should always make sure that the sensors react properly when you add chemicals. If they don’t, you should clean or replace them.


How do the sensors react to an acid ?

The pH decreases and the ORP increases.


How do the sensors react to a base ?

The pH increases and the ORP decreases.


How do the sensors react to a sanitizer ?

It depends on the type of sanitizer. Normally the ORP sensor should show an increase. However, if the sanitizer is highly basic – such as liquid chlorine (sodium hypochlorite) or even dry chlorine powder (calcium hypochlorite) – the pH will rise and the ORP may actually decrease. You must therefore bring the pH back down to the IDEAL range to get the expected increase in ORP.


How should I clean the sensors ?

Clean the tip of the sensor with a mild soap solution. To remove scaling, use a weak acid solution, such as white vinegar.


What about bromine ?

Bromine is another halogen that works as a sanitizer very much like chlorine. Because its molecular weight is higher, you need about twice bromine in parts per million (ppm) or milligrams per litter (mg/l) to generate the same sanitizing and ORP levels.


Can I use ORP with ozone ?

Ozone is an excellent oxidizer, but it has a very short lifetime so that you need to maintain a chlorine or bromine residual to generate enough ORP.


Can I use ORP with UV or metal ions ?

Despite the claims of many of their manufacturers, metal ion systems (copper and/or silver ions) are no substitute for a sanitizer as they do not work without chlorine or bromine residual. The National Sanitation Foundation (NSF) approval of these systems specifies that a minimum of 0.5 ppm of chlorine be maintained at all times. It is therefore easier, less expensive and more effective to maintain the sanitizer residual with an ORP/pH controller.


What is Water Balance?

Water balance refers to the prevention of corrosive or scaling conditions in water due to imbalance in inorganic components, mainly calcium carbonate. It is usually monitored with the Langelier Index. Besides pH, this index accounts for the effects of temperature, alkalinity and calcium hardness. The CHEMTROL® Programmable Controllers monitor and display the Langelier Index and resulting water condition automatically.


What is Total Dissolved Solids (TDS)

TDS refers to the accumulation of chemicals and solids that cannot be removed by filtration. Their concentration is measured through the increased conductivity of the water. When TDS becomes too high, the sanitizer loses its effectiveness and swimmers complain of salty taste and eye and skin irritation. The CHEMTROL® Programmable Controllers with the TDS option replaces the water automatically by dumping and refilling with fresh water.


What is Automatic Backwash?

Automatic Backwash reverses the flow of water through the filter (or filters) to remove the accumulation of debris resulting from the filtration process. The CHEMTROL® PC6000 Integrated Controller can be programmed to initiate backwash automatically according to a set schedule or whenever the differential pressure across the filter exceeds a set value. Multiple filters can be backwashed in sequence with adjustable wash cycles and wait times between filters.


What do you mean by Remote Communications?

The CHEMTROL® Programmable Controllers range offer a Remote Communication package include communication software to allow the operator to communicate with the controller in a true duplex capability from any PC-compatible computer using WINDOWS.


What are the advantages of Remote Communications?

With Remote Communications, the operator can check the operation of the water treatment facility from anywhere and at anytime and receive direct on-line technical support from the factory or local dealer.

CHEMTROL® Qualified Dealers can also provide this service of tele-servicing to their best customers.


What is Tele-Servicing?

With any CHEMTROL® Programmable Controllers, dealers and service companies can monitor their customers’ facilities using the remote operation program.

This service results in tremendous savings to both the dealer and his customer by reducing the number of unnecessary trips to the facility. It also gives his customer the assurance that the facility is receiving professional surveillance at all times.

By using the automatic computer scanning program, the dealer can also provide his customer with weekly or monthly reports on the operating data.


What about controller maintenance?

After initial adjustment, the CHEMTROL® controller requires little maintenance besides periodic cleaning of the sensors and testing of the water as required by the health department and common sense.


Why should I select a CHEMTROL® controller?

Our range of microprocessor-based controllers are the result of 40+ years experience of water treatment and chemical automation research and development. With 100,000+ installations worldwide, CHEMTROL® controllers are designed to be reliable and operator-friendly. Expert technical support is always available by a large network of Qualified Dealers worldwide. Learn more…