The Effects of Rain
Rain and other weather conditions have a big effect on your pool, so pool care must take some factors into consideration. In general, rain and wind add the following to the pool:
• Contaminants that provide food for algae and bacteria growth
• Contaminates that consume chlorine residual
• Fresh algae spores
Understanding the Chemistry
Rain and wind collect contaminates from the atmosphere as it falls to the ground. These contaminates have an immediate effect on the pool water. As contaminates enter the pool, the chlorine in the water, using its oxidizing power, will attack the contaminates. This will remove the contaminates from the water and simultaneously deplete the chlorine level!
Whenever contaminates entering the water exceed the amount of the pool’s chlorine oxidizing power, the free chlorine level will drop to zero and leave some un-oxidized contaminates in the water. The remaining contaminates feed the growth of bacteria and algae. Overnight, the pool can turn hazy and algae growth can become visible.
Rain often affects the pH also. Many rains are “acid,” thus causing the pH to lower. That’s why it’s important to monitor your pH after rains.
How to Respond
Regular, weekly shocking removes the normal amount of contaminates that build up in the water. Yet, a rain can suddenly add abnormal amounts of contaminates, which require an additional, immediate treatment. Whenever a pool is exposed to such rains and winds, you should practice the following:
1. Check the pH level. If the pH is low, delay adjusting the pH until after you’ve given the pool a chlorine shock, since most chlorine shocks slightly increase the pH. If the pH is high, lower it to 7.2-7.4 fast!
2. Check the chlorine level. If the chlorine level is below 1.5 ppm, give the pool a boosting shock of 1 lb per 10,000 gal. Use a granular chlorine such as Poolife Turbo Shock.
3. Whenever you see cloudiness or visible signs of algae, immediately give the pool a double shock of 2 lb per every 10,000 gal of water. You want to stop the growth and restore clarity before it worsens.
Hot weather results in warmer water temperatures. Warm water, specifically any over 84 degrees, causes the following:
• Increased chance of algae growth
• Increased consumption of chlorine
As temperatures rise, it’s important to increase your rate of chlorine feed to maintain the proper chlorine level (1.5-3 ppm). Use a potent weekly algaecide, such as Pool Baron's Rescue Algaecide, along with your weekly shock, to prevent algae growth.