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
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.
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.
