My pool chemical readings

[colrhino]

Going on our fourth season w/our pool, a 17,500 gal
in-ground gunnite pool w/a SWG and pebble tech bottom. Located in sunny GA, just outside Atlanta to the West. Finally got around to cancelling my pool service, against my wife’s wishes, due to apprehension about messing with a good thing (have never had the first problem w/our pool) and laziness, if I am to be honest, haha. I travel quite a bit, but our service was only every two weeks, so I figure I can do it at least that often, if not every week. Been talking to the pool guy and watching- the only thing I’ve ever seen him do is add muriatic acid and sodium bicarbonate. So I bought a Taylor K-2006-SALT test kit and here we go. Got the following readings today:
FC- 6.5
CC- 0
pH- 8.0
TA- 130
CH- 240
CYA - 30
Salt - 3800

So I know I need to add muriatic acid, about a quart, to bring the pH down. My TA looks high, my CH and CYA low, according to what I’ve read, if I am interpreting it correctly. What now? Thank you in advance for the assistance!

 

[duraleigh]

Welcome to the forum

Your numbers look pretty good. How does your water look? You can use a LITTLE tweaking on your results but let's make sure your water is nice and clear before we suggest a course of action.

 

[colrhino]

Thank you for responding, duraleigh. Our pool water is sparkling clear; always has been since day one, I am not exaggerating. Partly why I was hesitant to cancel my pool service. As in “if it ain’t broke, dont fix it” kind of thing. But I just felt that I could save myself some money by doing it myself. Plus I do everthing else such as lawn, auto maintenance, etc, as I am a DIY’er at heart!

 

[kabutotx]

I would just do an Overnight Chlorine Test (OCLT) to make sure nothings is in the water. Even a clear pool can fail sometimes.
When you pass you can push your CYA up.
For TA, test your fill water. If it is high it will just keep bringing it back up with evaporation. That is what happens to me. My fill is 140 so it just keeps creeping back up. To lower, use Muriatic Acid to reduce pH to 7.2 and aerate the water and repeat. Might take a few days. The SWG running is usually great at aerating the water.

 

[duraleigh]

When you lower your pH with muriatic the TA will move lower, too. As kabutotx says, the most permanent way to lower it is with acid/aeration method found in Pool School.

I would also suggest bringing your CYA up to around 60-70. You will reduce your chlorine consumption significantly and then keep FC around 3-5 ppm all the time.

I would also leave CH alone for now. I think you will see a gradual increase over the swim season so no need to boost it now.

You are in fine shape. The pH will tend to rise constantly in a SWG pool so that may be your most important parameter to keep in check Go swimming and enjoy the season!

 

[colrhino]

Thanks for the info. How do I raise my CYA level? And we have a waterfall that runs 4 hours a day, so the water is thoroughly aerated daily.

 

[Razorhog]

Thanks for the info. How do I raise my CYA level? And we have a waterfall that runs 4 hours a day, so the water is thoroughly aerated daily.

You'll need to buy CYA, commonly labeled in stores as Stabilizer. Look for stabilizer that is 100% Cyanuric Acid. I found some Clorox brand stabilizer at my local walmart. Use the pool math app to determine how much you'll need. Then, put that amount into old tube socks and hang them in front of returns in the pool to allow it to dissolve. Give 'em a squeeze from time to time to aid in the process.

 

[colrhino]

Much appreciated!