How's my fill water?

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S

Shmello

0
Aug 6, 2013
12
Sacramento, CA
Next week I'm filling up my pool for the first time. My fill water is:

pH 8.2
ALK 40
CH 30
Copper ND
Iron ND

As of now, the plan is to follow the NPC start up procedure. So after fill, the ALK is increased to 80 and the pH adjusted to 7.2-7.6. On day 2, CH is adjusted to 150.

Should I be concerned that the plaster will be exposed to such low calcium concentration for so many hours? I plan to discuss this with the plasterer, but I wanted to get some voices of experience to inform me on whether this is a significant concern or not. Any thoughts would be appreciated.
 
The Sacramento area does have soft water like that, in fact, the pH may actually be higher than 8.2.
Your concern about the low calcium level of the tap water is valid.

Once your plaster pool is filled with that tap water, it is likely that the TA, CH, and pH will all be slightly higher than what the tap water readings are, and that there will plaster dust all over the pool. That is because the soft tap water will dissolve away some of the plaster surface.

If the plasterer isn't aware of the Bicarb start-up (which I recommend), he probably won't want to try it. So you will have to see what you and plasterer can work out at this point. If you are having the pool plastered with color, that adds to the complication of pool start-ups.

If you want to learn more about proper plastering practices, see this post: ten-guidelines-for-quality-pool-plaster-t42957.html
 
The water was tested using the TF-100, doing the pH a second time for my wife to check with her more "color aware" eyes.

I brought a sample to Leslie's which tested it after it had been sitting for about 4 hours. They obtained the same results on ALK and CH, but their pH measurement was 7.8.
 
linen said:
I would test the TA and CH with your tf-100. Pool store results are very unreliable.
Click to expand...

I did those tests with the TF-100 as well (the results on those were the same as Leslie's). The only results which are exclusively from Leslie's were the metal ones, but the city water quality report also lists these as ND.
 
Pre-treating the tap water is always the best way. With that being said, yes of course, you can balance the water after the pool is filled. I think raising the alkalinity to 200 ppm and the calcium hardness to 200 ppm will be sufficient. You will need to add sodium bicarbonate to raise the TA, and at the same time, add acid to lower the pH to 7.4 to 7.8. Do not add calcium chloride (calcium hardness increaser) until the pH is below 7.8. That is important to make sure of that.

With blue colored plaster jobs especially, the start-up is important, but not as important as the quality of the workmanship of plastering. It is very difficult to achieve a uniform color without streaking. So I hope you read the post listed before and try to work with your contractor.
 
I need to mention that with your soft tap water filling the new plaster pool, the pH of the water will rise to about 9.0 (from pH 8.2 tap water) by the time the pool is full of water. So that will require more acid doses to help lower the pH, and of course, the acid will also reduce the alkalinity at the same time. So account for that when adding sodium bicarbonate to raise the alkalinity.
 

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I am in Antelope, my recent tests show a

pH 7.6
TA 120
CH 130

at the time
FC 4
CC 0

I have an AG pool so it is different. I have never adjusted my CH. My pH seems very steady and I only need adjust every month or so.
 
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