Trouble reading PH

[Switched]

Hi all,
Just did my first chemical test as a new pool owner. When I got in, found SWG running at 100%.
What I’m doing as the chlorine is high is turn SWG to 0% until FC is reduced, remove solar blanket during day and adding at night. Secondly I’ve added about 4kg of calcium but will wait until chlorine and PH is correct before addibg
More.

Free Chlorine 10
Other chlorine 1
Ph: 7.8
TA: 80
CH 250
CYA:30
Salt 4800

I’ve added some acid to bring down the PH but having trouble reading measurement.
See attached - can you give me your thoughts as to what it is?

 

[ajw22]

pH Test is Unreliable When FC > 10

When pH test reads higher then 7.8 assume pH is 8, use PoolMath to calculate reducing pH from 8 to 7.6, add necessary acid, wait 30 minutes, retest pH, repeat until pH is 7.8 or less.

 

[Texas Splash]

Differentiating between the shades can be difficult at times. Some find help holding the test sample up against a white background. Might help a bit.

 

[Jimrahbe]

S,

I have never seen a pH test tube like the one you show.. I kind of like it..

Please tell us where you got it and the brand name..

I too find it difficult to pick the right color..

Thanks,

Jim R.

 

[Texas Splash]

Please tell us where you got it and the brand name..

I'm going with CCL.

 

[Jimrahbe]

Pat,

I was hoping it was some brand that Clear labs just sells and not something they invented..

Jim R.

 

[Fuldo]

I also have a hard time determining PH levels in the 7.8 to 8.0 range. When in that range I do an acid demand test with just one drop of acid demand reagent. If the color appears to be in the low to mid 7s as it usually does then I believe the PH is 8.0 or lower and just on the cusp of needing adjustment. If that one drop indicates high 7s then I'll add acid. This seems to work for me.

Your signature indicates you have a Clear Choice Labs test kit and if so it probably doesn't include an acid demand reagent. I suspect that reagent is simple highly diluted acid and if so maybe you could mix some yourself if there's some documentation somewhere describing the method.

 

[johnpkaiser]

I also have a hard time determining PH levels in the 7.8 to 8.0 range. When in that range I do an acid demand test with just one drop of acid demand reagent. If the color appears to be in the low to mid 7s as it usually does then I believe the PH is 8.0 or lower and just on the cusp of needing adjustment. If that one drop indicates high 7s then I'll add acid. This seems to work for me.

Your signature indicates you have a Clear Choice Labs test kit and if so it probably doesn't include an acid demand reagent. I suspect that reagent is simple highly diluted acid and if so maybe you could mix some yourself if there's some documentation somewhere describing the method.

^
I do the same thing. I have the hardest time differentiating the color above 7.8

 

[AusPhil]

Pat,

I was hoping it was some brand that Clear labs just sells and not something they invented..

Jim R.

Fairly certain that Brett has those colour stickers printed for CCL. Honestly that tube looks good in theory but somewhat sucks in practice, might be ok if the bands stretched further around the tube.
the sample colour is not orange so it’s not low, it’s not pink so it’s not high.. I’d guess it was 7.6 but it’s a guess.
that tube is the reason I bought and promote the simple digital meter that can be calibrated.
cheers
phil

 

[Jimrahbe]

Phil,

I have tried two different digital meters and was not impressed, at all... Maybe it is just me...

Thanks,

Jim R.

 

[revitup]

I really like my Apera Instruments PH60. No guesswork, a straight digital readout. I calibrate about once a month but it's always pretty much right on. Minimal ritual of rinsing in distilled water and store wet in a storage solution. Stick it in the sample and go to the next test.

 

[Switched]

Thanks Everyone. Yep its the clear choice labs test kit.
OK it looks like the FC has dropped from 10 to 5.5 in the last two days now with pool cover off and SWG set to 0. CYA is actually less than 30, it could be 0 for all I know.
Sounds like the PH is still too high - tomorrow night I'll go ahead and add some more acid - I guess once I see it start to turn orange then I know we are closer to the mark.
In the meantime I'll research what an acid demand test is.
Thanks again