Heat Dome

It’s Hot, Hot, Hot!

Do you remember the cool, extremely rainy spring that just ended? It wasn’t fun. And now, we are blessed with a ‘heat dome’ that traps hot, extremely humid air. A two-mile-per-hour breeze doesn’t offer much relief. And folks, we’re just in the first week of summer. There are lots more days where just walking to the mailbox and back will leave you drenched in perspiration. For those lucky enough to have a swimming pool, be glad you have a great place to cool off. But just like us, pool water is affected by the heat. More specifically, the chlorine in the water is affected. I’ll explain five key elements in keeping that water clean, clear, and sanitized. After all, as the temperature continues to climb and the feels like temperature tops 100° Fahrenheit, you don’t want pool water that you’ve lost and is now pea green.

Proper chlorination.

It’s not enough to just tell you to keep an eye on your chlorine level. Here’s the scoop. Chlorine has levels of effectiveness based on ultraviolet (UV) rays that raise water temperature. In short, what worked in May or early June won’t work now. Keep an eye on the pool’s water temperature and adjust chlorine accordingly. For every 10-degrees of water temperature rise you need an extra 25% of chlorine. Go from 60-degree water to 70-degree water, add 25% more chlorine. Go from 70-degree water to 80-degree, add another 25%. And so forth. Some pool people out there say the percentage is even higher, with as much as a 50% additional requirement. I’m not sure that much is necessary, but if in doubt, err to the higher number.

pH.

pH, or potential hydrogen, is a measurement of how acidic (low pH) or basic (high pH) your water is. It’s a scale of 0-14 with ‘7’ being completely neutral. For pool water it is recommended to keep the level slightly basic in the 7.2 to 7.6 range. Some people use 7.8 as the upper number. Stay in that range and you’ll take a big step in keeping your pool swimmable.

Why is maintaining proper pH so important? It’s simple. A low pH causes chlorine to become hyperactive. That means it burns out quickly. UV rays and hot water dramatically shortens its life. You can have a high chlorine level one day and have it gone the next day. On the opposite end of the scale, chlorine is not effectively released into the water in high-pH situations. In other words, it’s there but not working effectively or at all.

Total alkalinity.

Okay…so you’re diligently adjusting the pH to keep it in the proper range, but you’re having issues. You adjust, but the next day the pH is off again. Your problem is probably your total alkalinity level. Alkaline content serves to hold pH steady and is measured in parts per million (ppm). Eastgate Pools recommends a range of 80-150 ppm. Staying in this range helps stabilize pH, which in turn, allows chlorine to work more effectively.

Cyanuric acid.

There’s one other chlorine aid: Cyanuric Acid (CYA), also known as stabilizer. This is a low-level acid that helps hold chlorine in the water by minimizing the UV effect. I always refer to it as a chlorine life giver. More accurately, it’s a chlorine life extender. Once added to the proper level of 30-120 ppm it tends to stay in the water quite well. Many chlorine tablets have CYA in them as a slow-release boost and will be listed on the label if so.

One Last thing.

If you use chlorine tablets or granular chlorine to sanitize and prevent an algae bloom, it is important to shock your pool with liquid chlorine weekly. This sudden boost serves two purposes. Firstly, the sudden boost can prevent algae problems before they start if you are on that precipice. Secondly, liquid shock removes chloramines from the water. These are chemical compounds formed from spent chlorine that has combined with nitrogen-based contaminants such as sweat or body oils. Here’s the kicker. Chloramines will give you a false chlorine level reading. If you don’t apply liquid shock you can test the water and get a good reading but have a green pool the next day. I recommend shocking weekly. Do it late in the day to avoid UV rays burning it out of the water and don’t splash it on your clothing. It’s like clothes washer bleach except it’s much stronger. That is unless you get old liquid frequently found in box stores. I recommend adding it on Sunday evening after everyone is done swimming for the day. Make sure the filter is running and don’t swim for several hours after adding as there will be hot spots that must disperse.

One last note about pool shock: Some people skip the shock because they just tested and the chlorine level was fine, possibly even high. Shock it anyway to get rid of those chloramines that might have just caused a false reading.

In summary…

Increase chlorine as the water temperature rises.

Keep your pH in the acceptable range to maximize chlorine effectiveness.

Adjust total alkalinity to help hold the pH steady.

Add cyanuric acid (stabilizer) to lengthen chlorine life.

Once weekly, add pool shock to eliminate chloramines that cause false readings.

Swim in clean, clear, perfectly balanced pool water and enjoy the summer.