So, you just can’t seem to get your pool free of algae? Or maybe the green is finally gone, but your water just isn’t that sparkly blue it was in the past? You are not alone! Between the heavy amounts of pollen that lasted well into the summer, the unprecedented amounts of rainfall we’ve had, and the repercussions from the northern wildfires, 2023 has been anything but a typical pool season.

Rain can affect your pH and alkalinity level, wash all sorts of natural material into your pool such as pollen and plant matter, and dilute your calcium and cyanuric acid levels, leaving your pool full of water, and lacking the chemicals that are meant to keep it healthy and swimmable.

This summer we had another factor to work around—wildfire smoke. The unanticipated effects on our pools from the fires in Canada included organic materials that had burned and wafted down through Litchfield County, and finally settled in your pool when the smoke settled. That put a higher demand for free chlorine in your pool water and increased your filter’s need for backwashing and cleaning.

In addition, we saw an increase of the chemicals that were used as fire extinguishers mingling with the smoke and settling in your pool. These chemicals include calcium and the stabilizer found in cyanuric acid (CYA). In the early part of the summer when the smoke was still thick, we tended to see low free chlorine, very out of balance pH, and high calcium and CYA readings. When the smoke cleared, it looked like the problem had cleared. But as the rain fell, it brought with it the residual chemicals in the atmosphere, meaning these calcium and CYA numbers continued to climb higher, while the rain washed in more plant material and pollen, further increasing your pool’s need for free chlorine.

So, what’s a pool owner to do? We would generally recommend shock, shock, and more shock to kill off any green that may be growing in your pool. An algaecide will give that chlorine shock the support it needs so that it can more effectively sanitize your water. Brush your pool well to disconnect those algae spores from their “life source” (the walls and floor) so that the free chlorine has that much more surface area on the spores to connect to and kill. Non-chlorine shock is also a suitable alternative when chlorine levels are already high and there is still organic materials and bacteria in the water than needs to be broken down and sanitized. 

So what does it mean if your free chlorine levels are very high and the pool is still green? A couple of checks and balances might help to determine why this is happening. First, is your pH in a healthy range (between 7.2 and 7.6)? If not, adjust that first. Out of balance pH not only can affect your chlorine’s effectiveness, but it can skew your CYA reading. 

If your pH is fine, but your CYA reading is higher than 100 ppm (between 50 and 100 ppm is ideal), and your free chlorine levels are consistently high, you may need to correct your CYA. Lowering your CYA reading may also be key to helping the free chlorine that is already in your pool. To lower your CYA, simply dilute what is there by adding fresh water. Remember, typical rainfall will dilute your CYA and calcium, but this summer because the rain brought with it the extinguishants from up north, these readings may have gone up. When you are satisfied with your CYA, replenish your calcium as needed. Remember calcium should be between 250-350 ppm. Sustained high levels of calcium can lead to mineral scale buildup, and sustained low levels of calcium can lead to cracks and breaks in your pool finish, fittings, and circulation system.

You may be feeling discouraged at this point in the season. Keep in mind this has not been a typical pool season, and more than a few pool experts have been left scratching their heads at chemical readings that used to be predictable but have taken us through the carousel ride of 2023. So stick with it folks, and don’t hesitate to ask for help.