pH & high range pH

[ryanmr]

Hello again everyone.....I'm using the API master kit to test my water & want to know if someone can explain the difference and importance of having both pH & high range pH tests for aquarium water. I understand lower pH values (5.0) being more acidic and higher values (8.0) being more alkaline or basic. I guess I don't understand the need for both tests. Does this high range test really pertain more to certain kinds of fish? I normally get readings of 7.6 for pH, & 8.2 for the high range pH test.

 

[rich311k]

It is for different PHs if you fall in the low card use it if your PH falls in the range of the high card use that one. Your PH is 7.6 the high is not needed for your water.

 

[ryanmr]

So if I understand you, I can just use the regular pH test and not worry about the high range test?

 

[KarlTh]

Isn't 7.6 the highest reading on the standard test? If so, then you should discard it and use the result from the high range, where 8.2 is somewhere in the middle. Conversely, if the result on the high range test were the lowest it could read, you'd discard that and use the standard range result.

 

[ryanmr]

That makes sense. The range for pH test according to the manual is 6.0-7.6 and the high range is from 7.4-8.8 so I guess I would use the high range range test since the normal pH test isn't going to give me a value of anything higher than 7.6. The 8.2 value is the correct value.

 

[KarlTh]

That makes sense. The range for pH test according to the manual is 6.0-7.6 and the high range is from 7.4-8.8 so I guess I would use the high range range test since the normal pH test isn't going to give me a value of anything higher than 7.6. The 8.2 value is the correct value.

You got it.

 

[ryanmr]

thank you=)

 

[Temeraire]

You are correct. Indicators only changes color within a given pH range (or whatever it is measuring). Anything above or below the range of the indicator appears the color of the lowest or highest pH on for the range it indicates. For this reason if your pH has been consistently at one extreme or the other, it is very possible that the actual value is greater or lower, depending on what end of the scale it is showing.