Too much rain can be a real drag on your summer festivities for sure. But possibly even worse, it can really wreak havoc on your water chemistry and undo all your hard work keeping your water clear.
Too much rain water can cause major problems for you. Whether it’s coming directly into the pool, or run off from landscaping and decks. Water that comes off your landscape can cause problems because of the inorganics (fertilizer). It can and will cause water balance problems and promote algae growth. When rain water and run off enters the pool, it can change your water’s pH, calcium hardness, total dissolved solids (TDS) and other chemical levels because it is diluting what is in the water. The magnitude of the chemistry issues you’ll experience will of course depend on how much rain you get. If your pH was already in balance, and the rain water is acidic, it can drop the pH and cause etching on plaster and metal parts. By throwing off the water balance, algae can also grow.
Test, test, and test again!
Keep ahead of the changes to your water by testing frequently during heavy rain periods. It is also a good idea to drain off the excess water, bringing your water level appropriate for proper skimming. If you have a Diatomaceous Earth (D.E.) or Sand Filter with a multi-port valve, you can simply put it from vacuum to waste mode (if available on valve) and eliminate the excess water without putting the water through the filter. If the rain is a consistent problem, pool owners with cartridge filters should consider installing an outlet valve, after the pump, to pump water down to the proper skimmer level.
Note: Always be careful not to drain the water below the skimmer, you could run the pump dry and cause other problems.
Let’s hope for blue skies this summer. Look for more chemistry tricks and tips throughout the summer here on our blog.