Mental mistake today closing my pool. Wanted some input on it.


Oct 26, 2019
I normally check my water chemistry and balance my pool myself when closing but today I decided to go to the local store I relied on 17 years ago when I bought home with a pool. I wanted to check calcium levels before shutting down and had to go out anyway.

My cover is on and I pulled the pool cleaner out today from under the cover to put away for the year.

So the pool store tech told me to raise my alkalinity was 90 and I needed to add 12 lbs of of Sodium Bicarbonate and then 2.25 lbs of Biogard Low N Slow to lower PH. I had a 15 lb Arm and Hammer and I had no dry acid so I bought the Low-N-Slow from him. It's a fast dissolving dry acid. My calcium was on the high side, in the 400s. I'm worried about etching in the winter and know calcium is an important part of that equation.

I wanted to make sure my pump would be circulating and accidentally put the timer on the wrong side of the trip/off. I thought I was setting it up to run but did the opposite.

Anyway I added the Sodium Bicarbonate with the pump running and waited 45 minutes and dumped 3 lbs of the acid in the shallow end of the pool right near where it drops off and immediately got my pole/brush and swept vigorously 6 or 7 times towards the deep end. I'm pretty sure I dispersed it pretty well.

The problem is I did not realize the pump was not circulating when I added the acid. Whoops. So long story short about 4 hours later I realized this and fixed the issue. I tested the PH and it was still high. I waited about 1 hour after restarting circulation and the PH had dropped to 7.5 from about 7.8. So it had not been mixing.

I wanted to ask any pool guys how much damage I potentially did to my plaster. It was a dumb mistake. I was putting around the yard working all day and just did not notice the pump was off before adding the low n slow. I'm just worried that a concentration of acid was lurking at the deep end of my pool screwing up my plaster for 4 hours. Again, the acid product is billed as fast dissolving and is very fine/granular stuff. I brushed vigorously where I dumped it so I'm pretty sure there was not a pile of it sitting in one place but I imagine a fine layer of it sank over the deeper end of my pool.

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