Ph Error With Taylor Kitk-2106

[philalethes]

Spa newbie here. I got Taylor K-2106 for going down the Bromine path 6 months ago.

While in Ashland Or I had difficulty with pH reading. Fill container to 44 ml mark, add 5 drops R-0004 indicator. Cap, shake, and read. Right? It always showed my pH too high. How do I know? Because I tested it against 5 other sets of test strips, since I suspected it was off due to water feeling too acidic.

I have some older pHydron test papers of various ranges: 5.5--8.0; vivid 3-9;Brilliant 0.0-6.0. I even went online and bought new wide spectrum from Edmund Scientific (1-14), and some 5.0-9.0 John Kyles No. 5090 from local drug store. Old or new they all agree so are viable.

I even bought new indicator from local spa store for Taylor kit. Same reading.

Now I have moved to east NV and get my water from our private springs. Time to set up the hot tub again.

First test is the Taylor. It shows pH in the purplish range 8.0. BUT every pH strip and paper says the water is 6.0.

Taylor may be the "cadillac" but something is seriously off. I don't trust it now.

Has anyone else had similar problem?

Here is Taylor results for my water before any treatment:

pH 8.0

pH strips 6.0

total Alk 90 ppm

Calc hard 90 ppm

[chem geek]

The Taylor kit says the following regarding the pH test:

Sanitizer levels > approx. 10 ppm may cause a blue-purple color resulting in false high readings. Wait for sanitizer level to decrease to normal levels and retest to assure an accurate reading.

Is your bromine level high above 10 ppm? You should call Taylor about this. Their pH reagent is standard phenol red though it has some chlorine/bromine neutralizers in it to reduce the interference at least up to around 10 ppm.

If you have high sanitizer levels, you can try adding 5 drops of thiosulfate chlorine neutralizer (R-0007) prior to adding the R-0004 indicator dye though the thiosulfate can affect the pH itself, but at least you might get something that makes more sense.

[quantumchromodynamics]

If you have high sanitizer levels, you can try adding 5 drops of thiosulfate chlorine neutralizer (R-0007) prior to adding the R-0004 indicator dye though the thiosulfate can affect the pH itself, but at least you might get something that makes more sense.

The Taylor book recommends using 1 drop of thiosulfate. I would start there first. I think that 5 drops might be too much.

Add the drop of R-0007 before adding the R-0004, cap and invert to mix, wait a few seconds, and then add the R-0004.

philalethes, you should also do an acid demand test to see what that indicates.

[philalethes]

If you have high sanitizer levels, you can try adding 5 drops of thiosulfate chlorine neutralizer (R-0007) prior to adding the R-0004 indicator dye though the thiosulfate can affect the pH itself, but at least you might get something that makes more sense.

The Taylor book recommends using 1 drop of thiosulfate. I would start there first. I think that 5 drops might be too much.

Add the drop of R-0007 before adding the R-0004, cap and invert to mix, wait a few seconds, and then add the R-0004.

philalethes, you should also do an acid demand test to see what that indicates.

1. I have NO sanitizer yet. I have done no other balancing so far.

2. I compared my Taylor kit to a neighbor's reagent style kit and it matched my pH. Our water has high calcium from mountain spring so I will accept that the default pH is 8.0. This means the test strips whether new or not are crap. I have ordered refill sensor for my electric mini lab pH sensor and this should be accurate ?!

3. I did the acid demand test. Taylor kit took 4 drops to reduce pH to 7.4.

4. I used the Taylor manual: to reduce pH using 20 Baume muriatic acid for 400 gallons (I have 340) add 1.47 oz. I did this 8 hrs ago; my pH just tested is still purple in the 8+ range!!!!

I remain befuddled.

[quantumchromodynamics]

When water contains high calcium levels, it is usually due to high levels of carbon dioxide in the water that dissolve the calcium from the ground. As the carbon dioxide off-gasses, the pH rises. High water temperatures and aeration of the water force the carbon dioxide out of solution. The same thing happens to a soda when it gets warm or gets shaken.

Do another acid demand test and add the amount of acid indicated.

[waterbear]

Another thing to look into is cross contamination. The same vial is used for the CH and pH tests and the CH testis done at a pH of above 10 (this is the purpose of the 20 drops of "calcium buffer" which is actually a solution of sodium hydroxide. If the vial is not cleaned well after the CH test and later used for a pH test it can contaminate the test and cause it to read high.