Rainwater has acidic properties, so it is not recommended to use rainwater to fill your pool. The acids in the rain negatively affect the chemical balance of your pool water. Most of the rain in the US is acid rain, which can cause your pool water to become corrosive and cause damage to your pool.
While it is not a good idea to use rainwater to fill your pool, you don’t have to worry about a little light rain in your pool water. To be safe, you should keep your pool water chemistry balanced as best you can. Just remember to rebalance your pool water after a rainstorm.
This article discusses rainwater and its effects on your pool water chemistry as well as other things you can and can’t use rainwater for.
Rain Affects Your Pool Water
As mentioned before, rainwater has acidic properties that affect the chemistry of your pool water. Rainwater affects not only the pH balance of your pool water, but the alkalinity levels as well.
If you have an inground pool, you must be careful about rain runoff entering your pool. Rainwater that runs off your landscaping or deck can negatively affect your pool water. When this runoff enters your pool, it affects your water’s pH, calcium hardness, total dissolved solids, alkalinity, and other chemical levels. It will also bring dirt and debris into your pool.
The more rain you get, the more it will affect your pool water chemistry. After heavy rain, it is especially important to balance your pool water’s chemical levels.
You should frequently test your water’s chemical levels, especially during periods of heavy rain. You should also drain excess water so that it is at an appropriate level for skimming.
Does Rainwater Increase Pool PH?
Due to acidic pollution in the US, rain decreases your pool’s pH. Your pool water becomes more acidic after a rainstorm.
You should keep your pool’s pH levels between 7.2 and 7.8. Pool water that is too acidic will irritate your skin. Increased pH levels also reduce the effectiveness of chlorine. Chlorine is what fights germs in the pool, so you want both your pH levels and chlorine levels to be at appropriate levels.
Treating the water in your swimming pool is a required task as a pool owner. To make it as easy as possible, we recommend using a weekly all in one pool treatment like this one by E-z Pool. This makes outdoor swimming pool maintenance easy by keeping your pool’s pH levels between 7.2 and 7.6.
Does Rainwater Affect Alkalinity?
Rain dilutes pool water, which affects its overall alkalinity. You want to make sure your pool’s alkalinity level stays balanced so that your pool’s pH remains balanced. When your total alkalinity is too low, the water may corrode your pool and promote algae growth.
Does Rainwater Affect Calcium Hardness?
Rain washes minerals and dirt into your water, which increases the calcium hardness in your pool water. The runoff also affects your pool water’s pH and total alkalinity.
How Does Runoff Affect Pool Water?
Runoff from a deck or landscaping brings pollutants into your pool water. It brings traces of fertilizer into your pool, including phosphates and nitrates. These nutrients will promote algae growth in your pool.
Final Thoughts
Rainwater sounds like pure, clean water. We should be able to fill our pools with it and clean our clothes with it, but this is not the case. Because of pollution, rainwater is acidic. Acid rain is not healthy and is not recommended to fill pools with.
Too much rainwater in your pool can irritate your skin and corrode your pool if you don’t treat your pool after it has rained, especially if where you live is prone to rain often.
Rainwater negatively affects pool chemical levels. After a rainstorm, you must rebalance your pool’s pH and alkalinity levels.
