PEP Tech

Pool Season 2021 is Almost Here

Are You Ready?

There is no doubt that last pool season was really unpredictable and very busy for many. Regardless of weather conditions or use of the pools during the typical off months the time is here to ramp up again. Warmer weather, longer days and school breaks are just around the corner. That means more chemical consumption, increased activity, and more swimmers in the pool. It also means the threat of algae in the pool. Time to get ready.

How Long Before A Pool Goes Bad

As weather warms up and more bodies dive into the pool sanitizer levels can get consumed rapidly. A pool that is exposed to increasing hours of sunlight can go through 1 part per million (ppm) of chlorine a day, even with cyanuric acid (CYA). Increased water temperature and swimmer load can lead to as much as 10 ppm of chlorine consumed within a week. So, what will happen if the chlorine you added on Monday fizzles out by Thursday? Well it takes algae about 8 hours to double in population in untreated water. Within 3 days there can be millions of algae present. When you come back the following Monday the pool could be well on its way to becoming a swamp.

Prevention Tips

If it has been awhile since the pool has been super chlorinated now is a good time to do a chlorine disinfect shock. This is accomplished by using enough chlorine to raise the free chlorine to 20 ppm. 12.5% liquid chlorine is the best way to accomplish this. It takes 3 gallons in a 20,000 gallon pool to get 20 ppm. Once the chlorine level has returned to below 5 ppm, test the pools for phosphate and do a phosphate removal treatment. Once, phosphates have been reduced add a good broad spectrum algaecide. After this consider ramping up the free chlorine level for a few weeks and monitor how it is holding between calls. Here is simple program to prepare for Spring:

  • Test all water chemistry parameters _" especially cyanuric acid CYA and total dissolved solids TDS. The TDS should not be 1500 ppm over what the TDS of the source water is. Test your source water TDS and the pool water TDS. If the pool is over 1500 ppm higher than the source water then the pool water will need to be diluted to lower the TDS. CYA should be no higher than 50 ppm.
  • Do a chlorine shock raising free chlorine to 20 ppm
  • Test and treat for phosphates once the free chlorine level is below 5 ppm. Phosphate level should be no higher than 500 ppb. 200 ppb is ideal.
  • Add a good broad-spectrum algaecide. Polyquat or a copper based are best
  • This could be a good time to add borates as well. Borate level should be no more than 50 ppm

Being proactive is better than being reactive. Now is the time to do some simple treatments that can help reduce the number of problems that can occur in the busy time of the season.

Terry Arko
Hasa, Inc