pH test hard to read

numberonenole

0
LifeTime Supporter
Mar 18, 2009
148
Woods of North Florida
I have the TF100 test kit. I have a very hard time matching the colors of the pH. The color I get when I test my water is never any of the options (7.5, 7.8, 8.2) and I just have a hard time guessing whether it is 7.7 or 8.0. I'm pretty sure it is high, I just don't know by how much. In an attempt to get a better idea I bought some pH strips and they are too general (just say pH level ok but don't give a specific reading). The pool store says it is 8.0 today. Even knowing that when I tested myself I just wasn't sure. Any suggestions for a better (easier to read) pH test? Thanks!
 
Was your pH above 7.8? If so it's too high. Add a pt of acid per 10k gallons (for your pool I would just call it 2 1/2 cups), wait about 30 min or so with pump running and retest. If still above 7.8 repeat. If not you are done.

the colors going from low pH to high pH are yellow 6.8 and lower, yellow orange 7.0 , orange 7.2, orange red 7.4-7.5, red 7.6-7.8, red violet 8.0 , violet 8.2 and higher
If the color is orange red to red with no pink or violet you are golden.
 
It is easier to determine the PH color if you hold it up to a blue northern sky on a sunny day or a sunlit white surface. Figuring out the color in dim lighting is very difficult at best. Practice also helps. You should be lowering the PH, as waterbear suggested, and that will give you additional opportunities to practice.
 
Oh boy! I've gotten lots of practice, but practice doesn't help of you are doing it wrong! I've held the test up to different sources of light, white pieces of paper, the sky, you name it, but it is the color variations that are throwing me off. There is a big difference (to me) between 7.8 and 8.2.
waterbear said:
the colors going from low pH to high pH are yellow 6.8 and lower, yellow orange 7.0 , orange 7.2, orange red 7.4-7.5, red 7.6-7.8, red violet 8.0 , violet 8.2 and higher
If the color is orange red to red with no pink or violet you are golden.
This helps me, though! I've never seen orange, but I have seen what I guess would be called red. But not red like this guy : :party: I think I have now a red violet kind of color when I test. I guess? I've never been good at slight color variations (nor at matching my clothes).

Thanks for the information. I'm better at guessing the pH now than I was yesterday!
 
I find it hard also, and I always thought I was good at colors. \What I do is try to look at the degree of redness. Then I ask myself is it more or less than 6.8? More or less than 7.2? It is strange how long it takes to convince myself that is one thing and not the other.

With fill water TA of 340 and lots of aeration from spa and waterfall I am always battling rising pH and find I need to add some acid twice a week it seems.

I have found this product online, but not ordered it yet. I wonder does anyone have any opinion about it?

https://www.microessentiallab.com/ProductInfo/F01-SHTRG-055080-SRD.aspx
 
When I'm in between colors I add a drop of acid demand (if violet-red) or base demand (if yellowish) to the sample to change the color to get a better feel for it.
Barry
 
anonapersona said:
I have found this product online, but not ordered it yet. I wonder does anyone have any opinion about it?
Wider range PH test strips, like that one, don't provide as clear a color distinction between similar PH values in the range used by swimming pools, compared to the standard phenol red test.
 
BC said:
When I'm in between colors I add a drop of acid demand (if violet-red) or base demand (if yellowish) to the sample to change the color to get a better feel for it.
Barry

Thats what i do. I've found that if i add one drop of the acid demand, it usually changes the color down to the next 0.2 increment. Sometimes i cant tell the difference between 7.8 and 7.6. With the acid demand drop, i can see it better and figure out what the reading actually is. But..if its not over 7.8, i dont mess with it. My pool tends to gravitate toward 7.8 and hold there.
I have taken water to work and used an actual pH meter and the phenol red test in the kit is pretty dead on.
 
Woodberg said:
The PH always seems to gravitate toward 7.8. Is it a problem keeping it there, or should I keep adding acid to lower the PH.
If your TA and CH are also high, then you're getting into the risk zone for calcium scaling. If the other levels are okay then the higher pH is probably not a problem, if it really does plateau there.
--paulr
 

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Looks like you have a gunnite pool, so you CH would be pretty high to be in the proper range. Higher pH will make the Ca start to drop out. Never seen it on my end since my pool is vinyl and my CH is around 80 ppm. My neighbor has a gunnite with a CH of ~400. Ive seen his scale at higher pH.
 
My latest test numbers are as follows:

FC 5
CC 0
PH 7.8ish
TA 100
CH 230
CYA 50
Water Temp 92 (yikes)

From what I've read, my numbers should be OK, I've been leaving my TA a little high because we are traveling some this summer and I use Trichlor pucks while we're away. I'm been trying to stay on the low end of the recommendation for using pucks. Would my TA level be contributing to the rise in PH?
 
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