Filling the pool after plastering

[JonnyG]

The only potential issue that I see is the iron in the water. With softening, we don't see a problem with the water. But the unsoftened water has left iron stains on my walkways and foundation. Last year I switched all of my sprinklers over to softened water (moved where we tap into the water supply to after the softener). I wonder if I can just add Calcium to the pool as it fills? Is that something you can buy?

JonnyG

[mshumack]

It will not be a problem to wait two days to fill the pool. The weather is cool enough. Just make sure the water guy doesn't cancel on Tuesday. Another option is to reschedule the plasters to after Memorial day. Right now you have time on your side, once the plaseter goes on your fighting the clock.

[JonnyG]

I have doubts on whether the water guy can make it until Friday next week and I do not want to postpone plastering since they have a 2-3 week backlog. I have made the decision to fill the pool with my well water (which is softened). Question to the experts - I use an iron out salt in my softener - any problems putting the softened water into the pool? Also, I have SWG on the new pool. I plan on backwashing the softener every 12 hours during the fill (although my incoming water is not very bad even without softening)

Thanks
JonnyG
30,000 gallon Shotcrete pool being plastered this weekend

[MarkC]

I would bypass the softener and use regular water for the fill. You want the water to have some calcium hardness in it. I also came across this statement on another web site:
maintain the pH at 7.2-7.6, the total alkalinity at 80-120 PPM and the calcium Hardness at 150-200 PPM. This will help keep the walls from being etched. If the water is soft or has a calcium hardness below 150 PPM, you must add calcium hardness increaser to the pool or the pool water will extract calcium from the walls.

[JonnyG]

I asked the local pool store guy (he's the owner and seems pretty knowledgeable and he also didn't try to sell me anything). He said that it would take years for the lack of calcium in the water to cause damage to the plaster. He suggested a few weeks after filling the pool that I add in calcium based on the water chemistry at that time. He is also felt it would be easier to deal with the Calcium problem of softened water then the Iron problem of the unsoftened water. Sounds pretty reasonable, what do you all think?

JonnyG