I went to Leslie's about a month ago & the guy told me that I needed about a half-gallon of acid in my 18,000 gallon SWG pool, so I added acid... about 40% of a gallon.
I had my water tested at Leslie's several days later, and it barely budged... from 8.4(?) to 8.3 (on 8/30.)
The 8/30 readings from Leslie's are as follows:
3483 ppm salt (high, but the other pool store said I was at 2600 & my pools control panel reads 3000)
3.27 ppm free Cl
0.5 ppm combined Cl
8.3 pH
106 ppm TA
143 ppm Ca Hardness
36 ppm CYA
He recommended 20-25 lbs of Calcium hardness, but he didn't have a significant quantity in until maybe the next truck.
Not realizing that my pH had barely budged, I figured in the meantime, I'd throw some chlorine shock at it & bought two bags of their really concentrated stuff, which I put in that night.
I got impatient about the idea of waiting for Ca Hardness, so I ended up going to another pool store the next day.
The other pool store gave me these test results the next day, on 8/31:
2600 ppm salt (massively different reading)
10 ppm free Cl (expected it to be high -- just shocked the pool)
10 ppm total Cl
8.2 pH
88 ppm TA
200 ppm Ca Hardness (somehow it magically went up?)
40 ppm CYA
Even the 8/31 test had me rather low on Ca Hardness, so I proceeded with adding 10 lbs of Ca Hardness.
It rained several days ago, and the pool's walls started to turn a bit green again.
Seeing as how the two different pool stores have me substantially different readings (3483 vs 2600 ppm salt, 143 vs 200 Ca Hardness, 106 vs 88 TA) and after realizing that my pH had barely budged even after adding quite a bit of acid, I wasn't sure if I should be skeptical of their test results or if adding the shock threw the readings off, so I ordered a Taylor K2006 off of Amazon so I could test my water much more often & know that I wasn't being played games with.
The K2006 came in on 9/10 & I tested the water yesterday, 9/11.
6.6 ppm free Cl
0.6 ppm combined Cl
8.2 pH
90 ppm TA
250 ppm Ca Hardness
20 ppm CYA (a little low, but I do have quite a bit of FC anyways)
(Note: I also added phosphate remover about a month ago [from 1500 ppb to 0], 10 lbs of calcium hardness on 9/1 [150-200 ppm to 250 ppm (as measured by new K2006)], and 2 lbs of chlorine shock on 8/30. All of these treatments were from quite a while ago, so they seem largely irrelevant & I should just go by what my K2006 tells me, right?)
I did the acid demand test as well, and the table said to add 1.72 qts, so I went ahead and added about that much in.
I tested the pH about two hours later, and it was 7.5, but I figured I'd add even more acid in, just to try to get rid of some of the new algae growth and I've already had trouble keeping the pH down, so why not? (I didn't test the pH again after adding the extra cup of acid, but I figured it should've put me around 7.4.)
I've added NOTHING in the past week or so except for this roughly half-gallon of acid yesterday.
Well today I go out there, about 22 hours later, and the pool is looking a bit better, but it's not perfect.
With that pH drop, we're on the right track though, so everything seems good, right?
Out of simple curiosity, I tested the pH again, believing that it'd be around 7.4.
I'm not at 7.4. I'm back up to 7.9.
Why is it that I've added nearly a gallon of 30-35% acid into my 18,000 gallon pool now, and I'm back up to 7.9 pH? Should I just keep adding acid until it stays down?
The pool was re-plastered a few years ago & the plaster seems to be damaged. Why is this the case, when my TA & Ca Hardness were relatively fine & my pH was through the roof? If anything, with the exceptionally high pH we've had in the past, we should have scale build-up, not plaster damage!
(Pictured: initial ~8.2 pH test from 9/11, and the ~7.9 test from today; I didn't take a picture of the 7.5 pH test from yesterday because I thought my pH troubles were finally gone.)
I had my water tested at Leslie's several days later, and it barely budged... from 8.4(?) to 8.3 (on 8/30.)
The 8/30 readings from Leslie's are as follows:
3483 ppm salt (high, but the other pool store said I was at 2600 & my pools control panel reads 3000)
3.27 ppm free Cl
0.5 ppm combined Cl
8.3 pH
106 ppm TA
143 ppm Ca Hardness
36 ppm CYA
He recommended 20-25 lbs of Calcium hardness, but he didn't have a significant quantity in until maybe the next truck.
Not realizing that my pH had barely budged, I figured in the meantime, I'd throw some chlorine shock at it & bought two bags of their really concentrated stuff, which I put in that night.
I got impatient about the idea of waiting for Ca Hardness, so I ended up going to another pool store the next day.
The other pool store gave me these test results the next day, on 8/31:
2600 ppm salt (massively different reading)
10 ppm free Cl (expected it to be high -- just shocked the pool)
10 ppm total Cl
8.2 pH
88 ppm TA
200 ppm Ca Hardness (somehow it magically went up?)
40 ppm CYA
Even the 8/31 test had me rather low on Ca Hardness, so I proceeded with adding 10 lbs of Ca Hardness.
It rained several days ago, and the pool's walls started to turn a bit green again.
Seeing as how the two different pool stores have me substantially different readings (3483 vs 2600 ppm salt, 143 vs 200 Ca Hardness, 106 vs 88 TA) and after realizing that my pH had barely budged even after adding quite a bit of acid, I wasn't sure if I should be skeptical of their test results or if adding the shock threw the readings off, so I ordered a Taylor K2006 off of Amazon so I could test my water much more often & know that I wasn't being played games with.
The K2006 came in on 9/10 & I tested the water yesterday, 9/11.
6.6 ppm free Cl
0.6 ppm combined Cl
8.2 pH
90 ppm TA
250 ppm Ca Hardness
20 ppm CYA (a little low, but I do have quite a bit of FC anyways)
(Note: I also added phosphate remover about a month ago [from 1500 ppb to 0], 10 lbs of calcium hardness on 9/1 [150-200 ppm to 250 ppm (as measured by new K2006)], and 2 lbs of chlorine shock on 8/30. All of these treatments were from quite a while ago, so they seem largely irrelevant & I should just go by what my K2006 tells me, right?)
I did the acid demand test as well, and the table said to add 1.72 qts, so I went ahead and added about that much in.
I tested the pH about two hours later, and it was 7.5, but I figured I'd add even more acid in, just to try to get rid of some of the new algae growth and I've already had trouble keeping the pH down, so why not? (I didn't test the pH again after adding the extra cup of acid, but I figured it should've put me around 7.4.)
I've added NOTHING in the past week or so except for this roughly half-gallon of acid yesterday.
Well today I go out there, about 22 hours later, and the pool is looking a bit better, but it's not perfect.
With that pH drop, we're on the right track though, so everything seems good, right?
Out of simple curiosity, I tested the pH again, believing that it'd be around 7.4.
I'm not at 7.4. I'm back up to 7.9.
Why is it that I've added nearly a gallon of 30-35% acid into my 18,000 gallon pool now, and I'm back up to 7.9 pH? Should I just keep adding acid until it stays down?
The pool was re-plastered a few years ago & the plaster seems to be damaged. Why is this the case, when my TA & Ca Hardness were relatively fine & my pH was through the roof? If anything, with the exceptionally high pH we've had in the past, we should have scale build-up, not plaster damage!
(Pictured: initial ~8.2 pH test from 9/11, and the ~7.9 test from today; I didn't take a picture of the 7.5 pH test from yesterday because I thought my pH troubles were finally gone.)
Attachments
Last edited:
