Newly re-balanced water, where to go from here

[geh]

A while back I posted my results from my Taylor K-2006 test kit as follows, with the biggest issue being my CYA way too high. I drained roughly 1/3 of my pool water and re-filled with tap water, added some chlorine and cyanuric acid to get to a ballpark starting point for balance. My old numbers were as follows:

FC 7.8
CC.04
Ph 7.5
TA140
CH 360
CYA 84

I'll break down my new numbers in one second, but I have a couple questions. When testing for CYA, it says "until black dot on bottom just disappears". What exactly does that mean? When its obscured and almost disappears, or the first moment when it absolutely cannot be seen? I have a pretty keen eye for discrimination (as a photographer by profession) and I can still barely see it when it up to the 30ppm mark. I recorded 35ppm yesterday and the pool store with their centrifuge type testing machine recorded 39ppm.

Have I gone too low in the CYA range through this exchange? I am also posting below the resutles of the pool store analysis, the Taylor book recommended range (PHTA guidlnes) and the pool math recommended ranges based on yesterdays test. I'm a bit confused why the pool math ranges are so different from the PHTA guidelines, although I suspect you will say the pool math ranges are based on my current chemistry. Another odd note, our water here in New Orleans is usually considered hard, so I'm confused why the numbers are coming back so soft, considering I just exchanged 1/3 of the water with municipal water. I tested my tap water and CH is 110ppm. I'm not touching borate until I get this stabilized, but I will be adding 20 mules to get my borate back up to a proper level after that. In the end, where do I go from here to get a better chemistry balance? So, below, first column is my Taylor test, second is pool store test, third is PHTA guidelines and fourth is Pool Math targets:

Taylor pool store PHTA Pool Math
FC 2.2 1.75 2-4 5
CC .2 .15 0 0
Ph 7.5 7.7 7.4-7.6 7.6
CH 210 188 200-400 450
TA 120 83 80-100 70
CYA 35 39 30-50 45

We had a lot of rain yesterday so I have to backwash a bit today and I suspect Ph went up as a result, so I will re-test today and adjust accordingly based on your recommendations. Thanks!

 

[geh]

That didn't format well but I'm sure you can decipher.

 

[mknauss]

According to your Poolmath data, just follow the FC/CYA Levels. Your other chemistry data is fine.
Start using a 10ml water sample for FC testing. One scoop of powder and each drop of R0871 is 0.5 ppm FC.

 

[geh]

According to the Pool Math numbers, my hardness is low, my alkalinity is high and my CYA low? I will be adding chlorine to raise the FC.

 

[JJ_Tex]

According to the Pool Math numbers, my hardness is low, my alkalinity is high and my CYA low? I will be adding chlorine to raise the FC.

Use the recommended levels from the link below. Overall your numbers look pretty good. TA is a bit high, but will come down if you just stay on top of knocking down the pH.
Your hardness is at the low end of ideal, but that is where I keep mine.
Your CYA certainly is not low, so please do not add any, but its certainly not unmanageable at your level of 90. (Edit - I missed the part that it was 90 before a water exchange).

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

 

[mknauss]

Ranges.
Recommended Levels
CYA is 40 (round up). TA is bit high but will come down as you keep the pH in the 7's. CH should be raised to 300 or so when you can. You will likely have to add calcium often as you get rain that will dilute your pool water. I suspect you could use Cal Hypo for chlorinating and that would add calcium. With rain overflow your calcium should be kept under control. But you would need to test CH monthly to monitor.

 

[geh]

Thank you both! greatly appreciate the guidance. I was particularly worried about the alkalinity and the longevity of the new plaster, as the pool was re-plastered this past summer. I feel better.

 

[geh]

When testing for CYA, it says "until black dot on bottom just disappears". What exactly does that mean? When its obscured and almost disappears, or the first moment when it absolutely cannot be seen? I have a pretty keen eye for discrimination (as a photographer by profession) and I can still barely see it when it up to the 30ppm mark.

Any thoughts on this? Am I looking for "completely disappeared?

 

[mknauss]

Any thoughts on this? Am I looking for "completely disappeared?

When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

 

[geh]

When you do the CYA test, try this next time.

Once you have your solution ready, back to the sun, etc. Fill the vial to a line, say 80, lower the vial to your waist level and glance for the dot, you see it, add solution to the 70 line, glance, see it, repeat until you no longer see it with a glance. Then use the CYA value one step above the line you read. So if you stopped at 50, use 60 ppm CYA.

The vial is in logarithmic scale. So it is not viable to interpolate between the lines. Just use the whole numbers, such as 50, 40, 30, ....

Thank you. I used that technique, arrived at 30 so I rounded up to 40. That matches with the sampling from the pool store that arrived at 39 yesterday, so I feel good about my CYA level. Appreciate the guidance on that.

 

[geh]

Revisiting this question. The first two levers on the left are my two skimmer baskets, in the open position. The lever on the right, I assume is my bottom drain? Should it be in that closed position or in the open position? My pool was re-plastered this past summer and wondering if the plaster guys closed it and forgot to re-open. I know very little about the plumbing of a pool system, and not sure what the function of the bottom drain is. Does it serve the same function as the skimmers, or would it drain the pool in the open position?
https://www.troublefreepool.com/attachments/unnamed-jpg.172249/

 

[mknauss]

Open it just a small amount. Say to 1 pm. Just enough for some water movement through it.

If you want to test that it is the main drain, open it, and slowly close the other two. See what the pump does.

 

[geh]

I added 5 lbs of calcium chloride today to bump up the CH a little. I'll adjust in small increments moving froward. Maybe another 5 lbs in a couple weeks, based on the test results. At what point will this new water and chemistry be stable enought to start adding Borax? My Borate level is down to 8ppm.

 

[cowboycasey]

It would be exactly like the skimmers just pulling from the main drain... To test if it works you can turn it on and slowly turn the skimmers off, if the skimmers get completely closed and the pump is still working the main drain is good

 

[mknauss]

You can add borates any time. But do NOT use borax. You will use massive amounts of acid to combat it. Use Boric acid.

 

[geh]

aa

 

[mknauss]

Is it literally a drain or does it function like the skimmers recirculating the water through the filter?

It is just another point for water to go to the filter. It is not required for proper pool operation. But since you have it, moving a bit of water through it is a good idea.

 

[mknauss]

Boric acid is available via Dudadiesel or other chemical suppliers. Get granular, not powder.

 

[geh]

It is just another point for water to go to the filter. It is not required for proper pool operation. But since you have it, moving a bit of water through it is a good idea.

Thanks and I just realized this was in the wrong thread.

 

[geh]

Would the granular boric acid be used in the same amounts as Borax? I previously used Proteam Supreme but it 's now around $160 for 45lbs. Thanks for all the help