How to drain and fill the pool


LifeTime Supporter
Apr 27, 2010
Fleming Island, FL
I am not needing to do this, but I was curious about draining and filling for correcting CYA or maybe even CH problems. I thought I saw a post, sorry can't find it right now, talking about exposing the finish during the process and that it could cause damage. I also worry about floating the pool if the level gets too low (live in Florida, water table is really high). Can you add water while removing water? Say put the hose in the shallow end and use the main drains on the deep end to take the water out?


TFP Expert
LifeTime Supporter
Apr 4, 2009
If really concerned about the high water table, you can approach this in small steps...drain 3-12 inches, will take longer, but even if you replace 10% of your water each time, your CYA concentration should come down by roughly the same % for each drain refill.


CYA = 90 drain 10%, CYA would theory be 81...repeat 81 minus 8 = CYA 73...etc


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
You can indeed add and remove water at the same time. For replacing up to around 50% of you water it can be quite efficient. If you are trying to replace a higher percentage it starts to get more and more inefficient. Ideally you want to add water at the top and remove water from the bottom, or the other way around. Either way, keeping the inlet and outlet separated as much as is easily possible.

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