Questions on pH, FC, TA, and CYA results

[KimBee]

If you wish to wait a couple hours before adding the acid as I noted above in post 38 that's fine. I just want to make sure you can tell now the pH is actually high, not low. Leaving it too high for an extended period of time leads to scale, especially in your SWG cell.

Yes I understand that, thank you.

Before adding anything else to the pool, I’m going to pick up some dI H20 and recalibrate my pH meter, too.

I came across something here on TFP about how to dilute a pool water sample with dI water to overcome the FC interference to get a better sense of a pH measurement with the test.

 

[Texas Splash]

I came across something here on TFP about how to dilute a pool water sample with dI water to overcome the FC interference to get a better sense of a pH measurement with the test.

Certainly up to you. I tend to keep it simple and not get into too much stuff like that, but feel free. Now that your SWG is off, with little to no CYA the FC should drop significantly today. Once the FC hits 10 do another pH test. It will be fine then. If the pH is still in the dark purple/lavender color zone, use the acid dosage I noted above to help lower the pH a little.

 

[BDY]

You said you have a ph meter - have you calibrated it lately or since you bought it? Most meters need calibration maintenance- for instance i make sure to do mine 1-2x a month. You can buy calibration solutions premixed or powders that you mix with distilled water.

Also - most meters the tips must be kept moist or else soaked in a storage solution for 30 min before testing. You can also buy storage solution online and be sure to put some in the cap of the meter while storing.

Last - if meter is placed in the sample vertically an air bubble can develop on the sensors be sure to place at angle and/or to gently swirl the meter to relieve any bubbles.

What kind of meter do you have?

 

[KimBee]

You said you have a ph meter - have you calibrated it lately or since you bought it? Most meters need calibration maintenance- for instance i make sure to do mine 1-2x a month. You can buy calibration solutions premixed or powders that you mix with distilled water.

Also - most meters the tips must be kept moist or else soaked in a storage solution for 30 min before testing. You can also buy storage solution online and be sure to put some in the cap of the meter while storing.

Last - if meter is placed in the sample vertically an air bubble can develop on the sensors be sure to place at angle and/or to gently swirl the meter to relieve any bubbles.

What kind of meter do you have?

Thank you for the tips! It’s a simple pen type pH meter with a cap that covers the probe so no mention of storing it moist in its instructions. (That said, I worked in a wet chemistry lab about 20 years ago and do recall our pH meter electrode being stored that way! And we calibrated daily with standard solutions, too. That’s all to say I’m older now and went for the cheap and easy route with my own pool pH meter )

I have a couple packets of the powder for mixing with dI water that I can use this weekend but I will looking into getting the prepared solutions you suggested. Thanks!

 

[BDY]

Thank you for the tips! It’s a simple pen type pH meter with a cap that covers the probe so no mention of storing it moist in its instructions. (That said, I worked in a wet chemistry lab about 20 years ago and do recall our pH meter electrode being stored that way! And we calibrated daily with standard solutions, too. That’s all to say I’m older now and went for the cheap and easy route with my own pool pH meter )

I have a couple packets of the powder for mixing with dI water that I can use this weekend but I will looking into getting the prepared solutions you suggested. Thanks!

In 2-3 weeks it gets off by 0.1 or so which to me is rounding error but I am I new to it so probably a bit OCD to start

I bought this one (lower mid range $….you can spend big sums on these if you want lab quality but it’s accurate enough for me and I keep my FC high enough that the comparator doesn’t work for me)

Meter
https://a.co/d/dxriZSk

Storage solution - they are pretty generic though
https://a.co/d/bKUxLRE

 

[BDY]

Ps - if you don’t have storage solution just use some drops of distilled water in the cap to keep it from drying out in the meantime

 

[KimBee]

I owe you all an update today and with much gratitude!

Results as of 20 minutes ago:
pH 7.3
FC 1.0
CC 0
TA 50

@Texas Splash - muriatic acid added yesterday and earlier today based on the Effects of Adding in the Pool Math app and the pH on the comparator block is now looking SO much better at about 7.3 (pic attached). Thank you tremendously for the advice

TA is holding at 50 now. Do I need to raise that still?

FC went way down to 1.0 since yesterday as you all predicted with lots of sun exposure, and used the app to set my SWG accordingly to bring it up today.

I purchased a gal of Natural Chemistry Instant Conditioner liquid stabilizer yesterday but haven’t added anything yet. Recall my CYA is zero and has been on multiple tests. Ok to add that now? Do I need to adjust my SWG settings with this stabilizer addition?

Thank you again - I appreciate all of the encouragement!

 

[Texas Splash]

PH and TA are much better. so leave those alone for now.

Two things to do now. Add the conditioner for a CYA goal of 60. Right now, also add 3 ppm of liquid chlorine to prevent algae.

 

[Texas Splash]

Wow, that CH is really up there. Before you add the conditioner, be sure to review the CH instruction to make sure you are using the correct sample size and reagent amounts. If it is that high, we'll discuss what to do about that next.

We'll watch for your reply about the CH and confirm if adding conditioner should be next or something else.

 

[KimBee]

Wow, that CH is really up there. Before you add the conditioner, be sure to review the CH instruction to make sure you are using the correct sample size and reagent amounts. If it is that high, we'll discuss what to do about that next.

We'll watch for your reply about the CH and confirm if adding conditioner should be next or something else.

Quick question - is violet considered “blue“ on the CH test? Pic attached. If that‘s blue for the purposes of this test, then it only took 7 drops just now and the CH would be at 175 ppm. (When I last ran the CH test over a week ago, I was looking for a true blue)

 

[clambert1273]

Quick question - is violet considered “blue“ on the CH test? Pic attached. If that‘s blue for the purposes of this test, then it only took 7 drops just now and the CH would be at 175 ppm. (When I last ran the CH test over a week ago, I was looking for a true blue)

I just use color change & when it stops changing lol

 

[Texas Splash]

CH should go past purple to a baby blue.

 

[IceShadow]

When it shifts, add another drop. If it shifts more, add another drop. When the last drop doesn’t cause a shift, subtract that drop, then you have your result.

 

[KimBee]

Thanks everyone. 27 drops of R-0012 to get to this blue. So 675 ppm.

 

[IceShadow]

High but not unexpected for SoCal. Be good to test the CH of your fill water at some point.

 

[KimBee]

High but not unexpected for SoCal. Be good to test the CH of your fill water at some point.

Yes, we filled the pool from the hose and already know our municipal water supply is hard - we have to routinely clean off calcium build up on shower heads, etc. in the house so this doesn’t surprise me.

 

[mknauss]

When did you do the fill? Your fill water CH is 250 ppm if it is from the Colorado River.

 

[KimBee]

When did you do the fill? Your fill water CH is 250 ppm if it is from the Colorado River.

Early February of this year as the placed fiberglass shell was backfilled.

 

[mknauss]

Then you must have added alot of calcium or been using a lot of cal hypo. There is no way your CH is that high from fill water.

 

[mknauss]

The sample may turn purple during the test, or go to blue for a moment and then turn back to red/pink. This is called a “fading endpoint” and is caused by interference from metal ions. If this happens, do the test again, but this time add five drops of R-0012 before adding any R-0010 or R-0011L. Remember to count the initial five drops in the total.
In extreme cases, a fading endpoint may occur even when adding five drops of R-0012 at the start. If that happens, mix pool water with an equal quantity of distilled water, test that, and then multiply the result by two.

I do the distilled water. Cut your pool water with equal parts distilled water. Then use that water for your test. Double the result.