Rainwater and Swimming Pools

rain poolIs it okay to allow rain water to get into your pool, or is it better to cover it?  This is a question that many new pool owners ask themselves the first time it rains after their pool is installed.  After all rain water is supposed to be fairly clean right? So how could it have a negative affect on your pool?

After your pool is installed you will find that there is some initial maintenance that you will have to do.  Basically you fill your pool with water and you then you will have to add chemicals, ie. chlorine, algecide etc. to make it healthy to swim in.  From there you will likely be checking your pool chemicals once a week to maintain that ideal amount.  Obviously this represents a fairly significant investment of time and money.  If you fall behind or just brush it off, and you are not keeping up with it then you may find yourself spending more time and money to get it back to where it needs to be.download

Rainwater can change the chemistry of your pool.  Just as it is, it can “dilute” the chemicals in your pool.  Ideally you want to keep your free chlorine level between 2 and 4 ppm. (Parts per Million) So this is based on the amount of water in the pool.  If more water is added to the pool then you will have to add more chlorine.  So if a lot of rain water gets into your pool, the amount of water increases and in turn you will have to add more chlorine.

LXI400P_LXiHeater-1-1Another thing that is likely to happen is really only an issue if you have a heater or heat pump installed.  Obviously it costs money to run a heater or heat pump.  That being said, if the set temperature is warmer than the temperature of the rain water (which it will likely be) then the cool rain water will decrease the temperature in the pool and you will have to run the heater or heat pump more often to maintain the desired temperature.
So back to the original question.  Is it okay to allow rain water to get into your pool?  The answer is really yes.  It is okay for rain water to get into your pool.  This will not cause enormous problems for the pool and in fact many pools are open to the rain all of the time.  However, if you have the luxury of covering your pool while it is raining, then I would certainly recommend doing so.  It will decrease the amount of time and money you put into maintaining your pool.