Ph, TA and CH Issues

JamesW

TFP Expert
Mar 2, 2011
16,599
Draining can only be done if it can be done safely without risking floating the pool.

What was the calcium hardness before the acid was added?

There might be copper in the water from the heat exchanger, but it's hard to tell.

I would get the TA up to about 60 and then retest everything including the copper level.
 
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ncbart

Member
Aug 5, 2019
12
TX
Recently I had white patches on my Quartzscape pool. I posted those issues back in a different thread. The pool resurfacing company came out and dumped several gallons of muriatic acid in the pool then tied a recirculation pump (so I wouldn't use my pool pumps) and left it there for a few days. After about 4 days of this, the white spots came out. He then put a few pounds of soda ash (approximately 3 pounds) in the pool to bring the ph back up. It has now been over a week and I did the full gambit of chemical tests and am having issues I haven't seen before.

FC: 7 (14 drops) I use mostly liquid chlorine
TC: 7.5 (added 1 drop R-0871 to bring it clear)
CYA: 50
CH: After adding 10 drops of R-0010 and 3 drops of R-001L I stopped adding R-0012 after 20 drops with little to no change (I did the test twice and stopped after 20 drops both times. The solution never turned blue)
TA: After adding 2 drops of R-0007 and 5 drops of R-0008 the solution never turned green. It was a light red/pink color so I didn't add any drops of R-0009.

My pool is very clear and I think my chemicals were quite balanced prior to them adding several gallons of muriatic acid.

Any help is appreciated.
I also had a similar problem. My pool builder (also in Houston) did a weak acid bath to remove some areas with excess plaster. After the pH was raised back to a normal level, the CH went from 200 to 700 almost instantly. I always suspected the acid bath made the calcium soluble.

I managed the high CH by keeping the pH and TA on the lower end until I planned to do a water exchange. Coincidentally, we got close to 30 inches of rain one morning during Tropical Storm Imelda which almost halved my CH to 350.
 

JamesW

TFP Expert
Mar 2, 2011
16,599
Pull the cartridge out of the filter. If you have copper in the water, the cartridge will usually show turquoise coloring.
 

BowserB

Silver Supporter
Jul 29, 2018
143
Katy, Texas
Hey Rick. If you shop HEB, check for baking soda there. There is an Arm & Hammer 13.6 lb bag for a very reasonable price. I don't know where you are in Houston, but I've found the Leslie's on Mason Road just south of I-10 to do pretty good testing. I've several times done tests with the TF-100 kit, then taken the water to this Leslies. Results have been very close--I think within the range of differences I get myself. I use them as a "second opinion" when I'm unsure of my own results. Also, their liquid chlorine, box of 4 gallons of 12.5% is $16, which is better than supermarket price, if you take into account the percent of chlorine (which is often a mystery in supermarket chlorine!)
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
I had just under 4 pounds of baking soda at the house. I mixed it in several buckets and put that in the pool. I also added 5 pounds of soda ash. I ran the variable speed pump all night at 2300 rpm. I tested the water this morning. The TA test would turn green after adding the 5 drops R-0008 (which it didn't before, it stayed red). After 1 drop of R-0009, it started to turn red but took 2 drops to keep that color. So, I'll call my TA a 20. This morning I added approximately 7-8 more pounds of baking soda. The ph test"s color is still yellow and not on the test kit so it is still below 6.8. I have 10 more pounds of soda ash here at the house. Thought I'd wait to see what effect the adding of the baking soda does before I add the soda ash. What do you guys think? Thanks
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
Also before adding anything yesterday, I cleaned my filters. They were not turquoise. If anything, once I sprayed them clean they were a touch whiter than usual. I guess that's from all the muriatic acid.
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
Hey Rick. If you shop HEB, check for baking soda there. There is an Arm & Hammer 13.6 lb bag for a very reasonable price. I don't know where you are in Houston, but I've found the Leslie's on Mason Road just south of I-10 to do pretty good testing. I've several times done tests with the TF-100 kit, then taken the water to this Leslies. Results have been very close--I think within the range of differences I get myself. I use them as a "second opinion" when I'm unsure of my own results. Also, their liquid chlorine, box of 4 gallons of 12.5% is $16, which is better than supermarket price, if you take into account the percent of chlorine (which is often a mystery in supermarket chlorine!)
I did get at HEB this morning. I'm down in Missouri City. I've found the 3 gallon 10% at Home Depot last week with a julian date in November. Have to buy 4 cases (12 gallons) to get it for around $9/case. Thanks.
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
Retested after 1 hour. TA now 60. ph still below charted color. Will now add 5 more pounds of baking soda as per the pool math app. Any idea if this clogs up my filter some? I cleaned it yesterday prior to adding all these pounds of baking powder and soda ash. pressure gauge up a little and less water coming out of the waterfall.
 

JamesW

TFP Expert
Mar 2, 2011
16,599
Keep an eye on the filter. Copper might not show until the pH gets to a good range.

The pH should begin to register soon.

It should be out of the danger zone now that you're getting a good TA reading.

Don't overshoot the target by adding too much baking soda.

I would avoid soda ash.
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
Retested.

TA: 90
ph: still below the color chart of 6.8 but starting to turn orange. Will call it 6.6
CH: at 36 drops of R-012 the solution went from red to purple (not blue) That would be a 900. At 40 drops it was still purple. I stopped there. Pool math app says I need to drain 73% of my pool.
 

Rick T

Well-known member
Apr 28, 2019
95
Houston, TX
during the CH test as I add R-0012 the red coloring seems to go from a uniform color solution to a bunch of tiny red dots in the solution. Not sure why. Did the same thing on earlier tests.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
That video above says to multiply the number of R-0012 drops by 10. The TF-100 kit instructions say to multiply by 25.
10 ML water sample size: multiply by 25
25 ML water ample size: multiply by 10

Also, next time you try a CH test (probably getting old by now), you might try increasing the R-0011 from 5 to 8 drops. I saw a similar post where Taylor made that recommendation as another way to help based on potential metals interference and/or magnesium.