With spring pool opening season upon us, ensure your service people are adequately informed with respect to electronic chlorination.
They need to be armed with a digital salt meter, cleaning stand and cell cleaning solution. Here’s a novel idea: why not print Owners Manual for the most common equipment out there and place them in the service trucks? The cleaning solution can be diluted Muriatic acid or a pre-blended formula from your chemical supplier.
Most manufacturers recommend periodic inspection and cleaning. Kill the power, then remove the chlorination cell for inspection. If debris or build up is present; use a high pressure hose to rinse. Do not poke or prod into the cell to remove build up; as this can damage the electrolytic blades. Only if necessary should an acid wash be done. Excessive acid washes will deplete the lifespan of the cell. I would suggest that the diagnostics be checked first and then if indicated, proceed with an acid wash.
As you are re-filling the pool, confirm the existing salt level before adding any appreciable amount of salt. Test with a quality digital meter to avoid any over salting. Test strips or titration testing are fine, however, strips and re-agents can become compromised over time. Additionally, the electronic controller or salt machine measures the pool water in a different fashion, using temperature, volts and amps and readings may differ substantially. A digital meter is the closest to this method. Over salting will require draining to bring the water to the correct salt level.
One note on digital meters; hold the probe tip in the water long enough for the meter to come to the temperature of the pool water. If the meter is on your dashboard or in a tool box, it could be frozen or overheated when you get to a job.
Make sure your staff at retail and in the backyard are aware that each Manufacturer recommends a specific salt level:
- Goldline by Hayward = 3200 - 3400 ppm
- Aqua Rite Low Salt by Hatward = 1200 - 1500 ppm
- Zodiac = 4000
- Jandy = 3000 - 3500
- Pentair= 3400
- WaterMaid =6000 plus ppm
This is also a good opportunity to take a closer look at the installation. Ensure that proper bonding has been implemented. Bonding is often overlooked and serves as additional protection against electrical shock as well as reducing corrosion potential. If not bonded, then recommend that an electrician (yours or the consumer) complete this important part of installation.
Galvanic corrosion occurs when unwanted galvanic cells (tiny batteries) are formed when two dissimilar metals come in contact in the presence of a conducting medium or electrolyte. Salt water is a great electrolyte. When the two dissimilar metals are connected, either by direct contact and/or electrical connection, a DC current is created. Electrons from the more active metal (the one with more free electrons) are transferred through the electrolyte to the less active metal (the one with fewer free electrons). The more active metal will eventually corrode away.
Electrolytic corrosion occurs when “stray electrical current” is introduced into an electrolyte, such as a pool of water. This usually happens because of poor electrical connections, poor grounding, and/or poor bonding of electrical equipment.
The above conditions should not be confused with electrolysis. Electrolysis is the degradation (breakdown) of an electrolyte (salt water) by passing the electrolyte through an electric current. This is what happens in a Turbo Cell. By passing the salt water through the cell, the salt (NaCl) is separated into a chloride ion (Cl) and a sodium ion (Na). The chloride ion (Cl) combines with the water (HO) to form hypochlorous acid (HOCL). The HOCL sanitizes and oxidizes the pool.
Corrosion problems in pools can occur in numerous ways, water chemistry, galvanic reaction, and/or electrolytic reaction. The more common ways of preventing corrosion in a pool are insulation by using a product called “AQUA LUBE”, plus installing non-metallic anchors for rails, ladders, & light fixtures, or installing sacrificial zinc anodes.
Problems? Or just too cool?
Before leaping to the conclusion that an electronic chlorinator is defective, and before adding salt, ensure the water temperature is consistently above 60 degrees F (15 C). Many manufacturers accommodate for low temperature as a protection, and to extend cell life.
Here’s how an AquaRite by Goldline behaves with respect to temperature:
Water temperature greater than 60 deg. F
Chlorine output relates to the desired output of percentage on selector knob. This is normal operation.
Water temperature greater than 50, but less than 60 deg. F.
Due to low temperature, the controller scales back output, and is limited to 20%, regardless of the "desired output %" selected.
Water temperature less than 50 deg. F.
Unit will be OFF (no chlorine is generated). LCD display will say "COLD" and the "Generating" light will flash.
The purpose of limiting or scaling back operation at low temperatures is to protect the electrode plates in the cell to ensure maximum cell life. The electrochemical reactions that occur in the cell will change, based on water temperature. As the temperature drops the cell generates more oxygen and less chlorine. The oxygen will attack the ruthenium coating on the electrode plates and shorten the cell life.
Below 50 degrees F, there is virtually no biological activity in the pool and therefore little or no chlorine is required. If the customer complains that they don't have a chlorine residual (free chlorine), tell them to run the unit for a day in Super Chlorinate. To initiate Super Chlorinate in "temperature scale back" mode, go directly from "OFF" to "Super Chlorinate". The chlorine generated that day should remain in the pool for a long time. A better option is to simply relax, and wait for the pool water to be consistently above 60 deg. F.
Between 50F and 60F there can be some biological activity and 20% of operational output should be more than sufficient chlorine production to take care of sanitizing the pool.
Recently, there has been plenty of talk and “marketing” with respect to Phosphates in pool water. Phosphates do not consume chlorine and they do not combine with chlorine. Phosphates; however, will promote algae growth and it is the algae that consumes the chlorine.
Phosphates are a food source for algae in the same way phosphates help your grass grow.
So, many people will say the phosphates in the water are eating my chlorine---WRONG! The algae being fed by the phosphates are what are eating the chlorine.
You have two choices:
Shock the pool and then keep the chlorine level high enough to prevent algae regrowth. Lower the phosphates using products such as Phos-Free by Natural Chemistry or an equivalent. At this point normal chlorine levels should suffice.
Before you leave the job, remind the customer that unless the unit is equipped with an automated chemistry option, such as the Goldline Sense and Dispense, they will need to periodically interact with the chlorinator to ensure correct water chemistry.
Article written by David Aitken, Sr. District sales Manager, Hayward Pool Products