Part of owning a pool or hot tub is learning to deal with everything Mother Nature might throw at you. While regular pool maintenance can keep your water pristine, the elements aren't subject to any routine. Most people think about things such as snow and dust storms, but rarely do they consider rain to be an aspect of nature they should worry about. The reality is that rain affects your pool or hot tub in multiple ways. However, this doesn't necessarily mean that rain is detrimental to your pool; it can be good or bad.
Rainfall and Water Chemistry
The water chemistry of a pool is very important; it needs to maintain the proper chemical levels to remain safe and comfortable for those that use it.
Rain can be acidic, so it can offset both your pH and alkaline levels. A pool should have a pH balance of 7.4 to 7.6, while some rainwater has a pH balance around 5.0, so heavy rainfall could lower the pH balance of the pool. However, while rainfall may distort your pH levels, it can also help dilute chemicals that cannot be treated with other chemicals and need to be diluted. The downside to this is that rain does not pick and choose which chemicals it will dilute. The result is that it affects every chemical in the pool.
That said, note that, although a heavy rain, or extended period of rain, may have an effect on your pool or hot tub, you don't need to worry too much about light rain, except for the algae spores which may wash or blow into your pool.
Rainfall and Debris
Rain seldom brings just rain; it usually comes with wind and anything the wind decides to pick up along the way. A good rainstorm typically brings along pollen, dust, algae spores, trash, and other organic matter, covering the surface and bottom of your pool. Not only this, but dirt and debris can clog your filter and pumps, making it more difficult to clean any other debris from the pool.
If any bushes or trees surround your pool, its susceptibility to contaminants is even greater, as they can throw leaves, branches, and oils into the water. However, perhaps the biggest concern when it comes to rain and your pool is algae. Rainstorms that bring in pollen and other plant matter, or even just disrupt your chemical balance, can promote the formation and spread of algae. It can be difficult to remove and repair any damage caused by algae growth, especially if left untreated for any period of time.
One of the biggest problems caused by rain is the accumulation of extra water. While this might seem like a given, excess water due to rainfall causes multiple problems. Heavy rainfall has the potential to cause flooding in any area, but if there's already a large body of water in the backyard then your chances of flooding increase. This can lead to extra runoff or debris in your pool and even flood necessary pool equipment, such as filters and pumps. A heavy rain can also cause the water level in your pool to rise rendering your surface skimmer useless in effectively skimming the surface debris to the skimmer basket, meaning you'll need to drain it back to the proper level.
Storm Prep and Repair
If you know ahead of time to expect rain, prepare by setting up your pool cover ahead of time. This keeps most of the debris out of the water. You should also store any loose items surrounding the pool, such as patio furniture, pool toys, and potted plants. This keeps them from blowing into the pool. Finally, turn off the pump.
Once the storm ends, turn the pump back on and remove the cover as carefully as possible. There is no sense in dumping all that debris into the water. Also, empty the skimmer and pump baskets. If you don't have a lot of debris at the bottom of the pool AND it took on a lot of water, go ahead and pump out the excess. If you do need to vacuum, hold off on dumping the excess water until after vacuuming.
Next, clean the pool as per usual: skim the surface, brush the walls and floor, and run the vacuum. Finally, test the chemical balance and make any necessary adjustments.
If you're looking for an easy way to ensure the water in your pool or hot tub stays balanced, consider a pHin smart monitor. This little device constantly monitors your water and automatically sends you exactly what you need to keep the water in your pool and hot tub healthy. If you're looking for someone to service your equipment, Pool Service on Demand instantly connects you to local, qualified pool techs.