Filling new pool with high TA water. How to proceed?

[tkakt]

We're having a new 14,400 gallon semi-inground pool put in next week. We plan to fill it from town water, but I tested the water this weekend and the TA reads 270ppm. We're going to have a SWG and I've read that high TA is bad for the cell.

So, what is the best way to proceed? Do we fill it, stabilize it, and use something else to chlorinate it until we can get the TA down with muriatic acid? Or is the TA level just too high so we'd be better off paying the $$ for a water delivery?

Thanks for the help!

 

[JasonLion]

Welcome to TFP!

You will need to add chlorine manually for at least the first day or two anyway, while the salt dissolves, and in that time you will normally be able to get the TA down enough so it will be safe to turn on the SWG.

The real risk is the combination of PH, TA, and CH levels all being somewhat high at the same time. You can use the Pool Calculator to figure out your CSI, and if CSI is above 0.3 you will want to hold off on using the SWG. Chances are that your CH level won't be all that high and things will be alright as long as you monitor the PH and work on lowering TA. However if CH is also very high in your fill water things can be more problematic.

With very high fill water TA levels you might want to investigate getting an acid feed system. High TA along with the SWG will drive up the PH fairly steadily. And even if you do get the TA down, adding more water will just bring it back up again.

 

[Richard320]

Welcome!

Wow, your water is worse than mine!

Shop around to find the lowest price for acid, as you'll be using a lot of it, especially at first. Just get the water balanced as a bleach pool and when you have pH fairly steady and the CYA is dissolved, add salt, give it a day to dissolve and mix, and start the SWG. Check out the highlighted post for a neat idea.

 

[tkakt]

Thanks for the advice!

So, can I start by adding the bleach and muriatic acid until the pH, TA, and chlorine look good and then add the CYA and salt? Also, is it okay to have the high TA water flowing through the SWG as long as it's off?

Diamond Day! Love it! (esp the free labor!)

 

[linen]

Welcome to tfp, tkakt

I too have high TA fill water.

It is fine to have the high TA fill water going through the cell when off.

Have you seen this pool school article?: http://www.troublefreepool.com/pool-school/lowering total alkalinity

 

[Richard320]

Thanks for the advice!

So, can I start by adding the bleach and muriatic acid until the pH, TA, and chlorine look good and then add the CYA and salt? Also, is it okay to have the high TA water flowing through the SWG as long as it's off?

Diamond Day! Love it! (esp the free labor!)

pH first. If it asks for more than half a gallon, split the doses.The acid will take half an hour or so to mix. Pump on, of course. While that's happening, measure out the appropriate (http://www.poolcalculator.com/) amount of CYA into an old sock or nylon. Tie it off and suspend it in front of one of the returns. Recheck pH. Adjust again if necessary. Give it another half hour to mix, then add the bleach to get you to about 3. Until the CYA dissolves, which will take a few days, expect to lose a lot of bleach to the sun, so check it a couple times a day. By about day 3, raise FC to whatever the recommended FC level is for your target CYA. Just assume it's there. It won't register perfectly on the test for several days, so give it a week before testing. But check pH, TA, FC every day at least and keep things adjusted.

I'd guess by Friday you'll have the TA knocked down to a reasonable number so the pH will be fairly stable and the pool will be looking good. So you can have Diamond Day on Saturday and fire off the SWG on Sunday. As a side benefit, a bunch of kids going berserk with the salt will also aerate the water good, which saves you having to rig up some contraption to do it.