The domino effect in 2021: Stretching chemicals in the era of shortage

by brittney_cutler_2 | January 22, 2022 8:30 am

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By Terry Arko

In Aug. 27, 2020, Hurricane Laura barrelled onto the Louisiana coastline with winds of up to 241 km/h (150 mph). Lake Charles, La., took the brunt of the storm, and it was sometime during this the chlorine plant owned by Biolab caught fire. After burning for three days, when the fire was finally extinguished, it was evident the plant had burned to the ground.

This facility produced approximately 40-plus per cent of the trichloroisocyanuric (trichlor) and disodium isocyanurate (dichlor) in North America. This event was the opening scene in what would become a harrowing story of environmental and economical conundrums. In February 2021, of all places, the state of Texas experienced a deep freeze which crippled the manufacturers of plastics and other petrochemical products. This resulted in 75 per cent of polyethylene, 62 per cent of polypropylene, and 57 per cent of polyvinyl chloride (PVC) production shutting down.

Prior to the 2021 pool season, the news and social media were abuzz with stories about a pending chlorine shortage that would make it difficult to keep pools sanitized. Trichlor tablets were in short supply and the prices in some areas had tripled from the previous season. As a result, many made the switch from trichlor tablets to either calcium hypochlorite (cal-hypo) or liquid sodium hypochlorite (liquid pool chlorine). The sudden increased demand on these other chlorine choices created a strain due to the shortage of plastic containers for the cal-hypo to raw ingredient supply for the liquid. Add to this the labour shortage, lack of containers, truck drivers, rail cars, and the overall increase of fuel and transportation, it created the perfect storm which was the summer of 2021.

There was one additional proverbial straw to break the camel’s back. In August 2021, OxyChem announced it was shutting down its Niagara Falls, N.Y., chlor-alkali plant. A chlor-alkali plant is vital in providing the raw materials for many chlorine-based products including liquid pool chlorine. This could create a supply chain shortage in some areas of the Northeastern United States and Canada.

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What to expect next

What does the forecast for 2022 look like in relation to chemical supplies? Many manufacturers are stating the supply of material or products will not be as much of a problem as it was last year. However, the packaging and transport to get the products into the marketplace could very well remain problematic.

This means longer waits on orders and allowing for longer delivery windows when placing orders. Preparing for the pool season now may make sense, along with getting early orders placed well in advance of spring start-up. The definite paradigm shift of 2020 was the pool industry working together to determine the best ways to make chemicals work more effectively and conservatively. The author has spent the last six months working with pool pros to help them understand the best ways to make chlorine perform its job and last longer in the pool. The following was put together to bring a greater understanding of the strength, proper dosing, and additives that can provide quality water for longer periods with better cost.

Ways to stretch chlorine

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The first thing one must determine to get the most out of chlorine is the true strength and proper amount to dose. Many times, liquid chlorine is over-dosed due to a lack of proper understanding of its true strength. Based on kilograms per litre (pounds per gallon), liquid chlorine delivers the highest amount of free available chlorine (FAC). Many in the industry are under the misconception that liquid is the weakest form and, therefore, requires more of it to be added to the pool water. The bullet points below show that litre to kilogram (gallon to pound) liquid provides the highest free available chlorine level in 37,854 L (10,000 gal).

• 3.78 (1 gal) 12.5 per cent liquid = 12.5 parts per million (ppm) of free available chlorine in 37,854 L.

• 0.45 kg (1 lb) of trichlor tablets 90 per cent = 11 ppm free available chlorine in 37,854 L.

• 0.45 kg of 65 per cent cal-hypo = 7 ppm free available chlorine in 37,854 L.

During hot summer months, a pool may go through 10 ppm of chlorine a week, even with cyanuric acid (CYA) kept at proper levels of 30 to 50 ppm. Therefore, 3.78 L of liquid chlorine in 37,854 L would last more than a week during the summer. The 10 ppm that is lost in the period of a week is all from demand.

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To keep pool water safe for swimmers, the chlorine must do more than just address demand. It must also leave a measurable residual behind in the water. The ideal residual recommended by Health Canada and other organizations such as the Centers for Disease Control and Prevention (CDC) and the Pool & Hot Tub Alliance (PHTA) is minimum 1 ppm of free available chlorine in pools not using CYA as a chlorine stabilizer. In pools using chlorine stabilizer CYA at levels of 50 or above, the minimum recommendations are 2 ppm of free available chlorine. The Environmental Protection Agency (EPA) has set a maximum of 4 ppm free available chlorine in public pools when bathers are present.

Based on the CYA to free chlorine dose ratio of 7.5 per cent, it is conceivable that the standard of 2 to 4 ppm may not be enough.

Managing the CYA is another way to use less chlorine. At a CYA level of 30 ppm, it will take only 2.25 ppm of residual chlorine to keep the pool free from bacteria and algae.

CYA to free chlorine ratio – 30 x 7.5 per cent = 2.25 ppm

At a CYA level of 100 ppm, it will take 7.5 ppm to keep the pool free from bacteria and algae. High CYA level is one of the biggest ways that chlorine is wasted.

100 x 7.5 per cent = 7.5 ppm

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Also, it is important to see here that at a CYA level of 100 ppm, one must exceed the EPA maximum allowable free chlorine level to keep pool water safe. Obviously, in public pools this would be of concern. This is why the standard recommendation of CYA at 30 to 50 ppm is so important.

Managing total dissolved solids (TDS) is also key to stretching chemical use in pool water. That said, pool pros should be testing for TDS at least three times a year in a residential pool. Further, one should also know what the TDS of the source water is. The reason this is so important is because if the TDS of the pool water is 1500 ppm over the source water, then 50 per cent of the chlorine being added to the pool is being wasted. The buildup of solids in the pool makes chlorine less effective. Regular dilution of the water can help to save on the amount of chlorine that is needed to keep pool water sanitized.

Borates are also great for helping chlorine to be more effective. With a level of borates in the pool at 50 ppm, one can use half the amount of chlorine that would normally be needed. If the pool water’s free available chlorine runs at 3 ppm, it can be cut in half to 1.5 ppm by using borates. Also, using borates at 50 ppm reduces the CYA to free chlorine ratio from 7.5 per cent to five per cent. For example, if there is 100 ppm of CYA, one would need 5 ppm free chlorine.

100 x 5 per cent = 5 ppm

Secondary disinfection systems such as ultraviolet (UV) and ozone pool sanitizers are excellent at oxidizing and reducing the formation of combined chlorine. When using these systems, it also allows one to run their chlorine at much lower levels. Advanced oxidation process is one of the latest technologies which incorporates UV, ozone, and hydrogen peroxide to create hydroxyl radicals. Hydroxyl radicals are the most powerful way to destroy bacteria, algae, and contaminants in water. However, they are very reactive and last less than a second in the water. They can help to reduce the chlorine needed to sanitize the pool water, but these units are not a replacement for chlorine. Further, a minimum chlorine residual of either 1 ppm without CYA or 2 ppm with CYA is still needed. Any type of an additional oxidizer will help increase the effectiveness of chlorine in the pool water.

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Balance is the secret

The secret to good pool chemistry and to the increase and effectiveness of chlorine in the pool is balance. Water that is balanced with proper CYA and borates will be the best quality with the least amount of chlorine needed. While standards are in minimum, maximum, and ideal, it is suggested to aim for the following target levels:

• pH 7.5

• Total alkalinity 90 ppm

• Calcium hardness 250 ppm (vinyl-lined or fibreglass pool) and 350 ppm (plaster pool)

• Cyanuric acid 30 to 50 ppm

• Total dissolved solids no higher than 1500 ppm over start-up

• Borates 50 ppm

In today’s world, one may not always be able to control the supply chain; however, what can be controlled is what chemicals are being used and how they are applied. By employing these techniques, homeowners and pool pros alike should see an improvement in water quality with less chlorine or specialty chemicals needed.

Terry Arko is a product training and content manager for HASA Pool Inc., a manufacturer and distributor of pool and spa water treatment products in Saugus, Calif. He has more than 40 years’ experience in the pool and spa/hot tub industry, working in service, repair, retail sales, chemical manufacturing, technical service, commercial sales, and product development. He has written more than 100 published articles on water chemistry and has been an instructor of water chemistry courses for more than 25 years. Arko serves as voting member on the board of the Recreational Water Quality Committee (RWQC). He is a Commercial Pool Operator (CPO) course instructor, a teacher of the Pool Chemistry Certified Residential course for the Pool Chemistry Training Institute (PCTI), a California Pool and Spa Association (CPSA) board member, and a member of Pool & Spa Marketing’s editorial advisory committee. He can be reached via email at terryarko@hasapool.com[7].

Source URL: https://www.poolspamarketing.com/trade/features/the-domino-effect-in-2021/

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