Chlorine Generator

Chlorine generators make chlorine from salt in your pool or spas water. You simply add salt to the water and the chlorine generator does the rest. The typical salt concentration is 2000 to 4000 ppm, at 3000 ppm that is about 2 pounds of salt per 100 gallons of water. Chlorine generators are very popular because they eliminate the buying, storing, transporting and handling of chlorine as well as provide a dramatic reduction in the maintenance demands of your pool or spa.

Self Cleaning

The chlorine generator has titanium plates with a special rare-earth coating that can have a build-up of calcium or other compounds over time. That is because during the electrolysis process current goes in one direction from plate to plate. Chlorine generators with the feature of self cleaning periodically reverse the direction of the current which helps to break up the compounds that have attached to the plates. If the hardness of the water is very high even self cleaning chlorine generators may still need to be cleaned, but not as often as those without self cleaning.

Adjustable Power

Chlorine generators typically operate at full power. To adjust the power they adjust how long they are on. A chlorine generator operating at half power may be on for 12 hours in a day, and off for 12. Chlorine generators without adjustable power usually need a timer added so you can externally control the amount of chlorine produced. Without controlling the chlorine production you can end up with too much chlorine. You can also adjust the chlorine production by increasing/decreasing the salt level but this can be a hassle.

Slow Chlorine Production

Chlorine generators make chlorine slow and are usually rated in production terms of ounces per day or pounds per day. If you need to shock your water usually chlorine has to be manually added as a chlorine generator can’t make a lot of chlorine all at once.

Other Chemicals

Chlorine generators have less effect on the overall water chemistry than other forms of chlorine reducing the need for water balancing chemicals. Chlorine generators also make chlorine every day reducing the chance that there will be days without a sanitizer which also reduces the chances of green water. The electrolysis process of a chlorine generator does tend to increase the pH so with a chlorine generator you will need to measure and adjust your pH every week.

Chlorine Generator Sizing

The titanium plates in a chlorine generator are expensive and the most expensive part of the generator. Units with higher chlorine production usually have more titanium plate area and are therefore more expensive. The most common chlorine generators are in-line, meaning they are plumbed into the piping of the pool/spa equipment. This also means they can only be on when the main circulation pump is on, or water is flowing across the titanium plates. If your chlorine generator has a low production rate you may have to run your pump longer to get the desired chlorine level.

Convection Chlorine Generators

This type of chlorine generator isn’t plumbed into the existing pool/spa equipment and isn’t tied to the existing equipment in any way making installation very easy. Usually, just plug in the power supply to a GFCI protected outlet, and then hang the chlorine generator cell over the side of the pool/spa into the water. This type of generator can have a lower production rate as it doesn’t require the existing circulation pump to be on.

Life Span

The coating on the titanium plates determine the life span of the cell and it typically 10,000 hours of chlorine production. This life span is dependent on the current going through the plates and as the current goes up, the life drops.

pH and total alkalynity are important components in water balance. I get asked quite frequently how to manage these parts of water chemistry. For pH you can use white vinegar, muriatic acid or any of the pH down products both dry and liquid that you can find at a pool supply.

For lowering alkalynity , dry acid works best or you can slowly lower it by maintaining a pH of 7.2 in your hot tub for a week or 2. To raise alkalynity, add baking soda or any alkalynity increase product at your pool supply.

You will want to keep your pH in the range7.2 to 7.8 and your total alalynity between 80 and 140. A lower alkalynity will make it easier to lower pH and a higher alkalynity will make  your water more resistant to pH changes. Where you need to keep your alkalynity is dependent on your hardness level. The harder your water, the lower you will want to keep your alkalynity and pH and the softer your water the higher you will want to keep it within the range.

Many a spa problem or spa trouble can be linked to improper spa maintenance. Always follow the spa owners manual when It comes to spa maintenance. You may be surprised that once you have your spa that it takes a lot more time in spa maintenance than you were expecting. If the chemical balance is far off it may take some time to bring the chemical  balance back into balance. The addition of a chlorine generator to the spa install has been found to drastically reduce the spa maintenance. A chlorine generator requires adding salt to the water hence making salt water. The salt water lasts a very long time before more needs to be added and typically the only thing you need to watch out for in spa maintenance is the pH level.

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The issue of corrosion continually comes up as a mystery and it really doesn’t have to be. Before chlorine generators arrived on the scene here in the US, we had regular old pools and spas that had corrosion issues. Many of these pools & spas were treated with liquid chlorine and had high TDS levels. The reason for this is that high TDS levels increase conductivity, letting stray currents to run through the water. Further investigation with sensitive instruments revealed that these bodies of water were not grounded properly. This was the cause of the corrosion. The only practical way to deal with this was to place zinc balls in the skimmers and inspect them monthly to make sure there was no scale buildup as this makes them ineffective and they will need to be acid washed so they will do their job, which is to help neutralize the stray currents in the water. Ocean boats use zinc anodes to prevent corrosion but here the salt concentration is 10x higher. It takes such a small amount of current that most people would never even detect its presence. This problem is much easier to deal with in a hot tub as you can make sure it is properly grounded with minimal effort. For extra peace of mind, you can always place a zinc ball in your hot tub’s skimmer.

Just about every major pool and spa equipment manufacturer has chlorine generators in their equipment line ups. In fact, chlorine generators are now being purchased on 50% of all the new pools being built in the US. Most of these have gas fired heaters which creates a hot water environment in the presence of a very soft metal (copper) and there are no salt water corrosion issues with these applications. I have personally installed and maintained salt water spas in health clubs and not found corrosion to be an issue.

I know of several hot tubs that have been on chlorine generation for 3 years or more without any signs of corrosion whatsoever. In fact, in our test spas the heating elements have been inspected on an annual basis for 4 years now with no corrosion damage.

What about CYA and does it prevent corrosion? This can be a controversial subject but here is the reality. CYA is not recommended for spa use because it lowers the ability of the chlorine to oxidize which is measured by ORP – Oxidation Reduction Potential. This can be witnessed in any pool or spa with an ORP controller. With a spa, the hot water will degrade the chlorine faster than sunlight and since I rarely ever see a hot tub that isn’t covered, why use it? CYA itself has a corrosive nature but it does lower oxidation levels which could potentially be beneficial with high levels but it also requires higher levels of chlorine to effectively sanitize. If you use CYA in a spa, it will take more chlorine to keep it sanitized. Very high levels of chlorine will cause corrosion.

Where to drain your tub? I would suggest running a hose to the street or into a toilet. Get an inexpensive sump pump that hooks up to a garden hose and be done with it. It works much better and quicker than the drain on the hot tub.

Simplify your spa or hot tub maintenance with the ColorChlor Spa chlorine generation system. Uses salt, baking soda and white vinegar to save you time and money. Greatly increases user comfort by softening your skin and getting rid of that funky hot tub smell. Go to www.spachlorinator.com or call 800.573.3495 for more info.