PPM - Don't Quite Understand

[LGLDSR73]

Good morning,
Trying to better understand Parts Per Million. Is a FC of 8.6 read as 8.6ppm or am I way off base?
Thank you!
Lyman

 

[mknauss]

Correct. 8.6 ppm if the FC is measured using the FAS-DPD test.

 

[JohnT]

Yes. PPM is a concentration. CYA, CH, TA, salt, borates and chlorine (free, total and combined) are measured in PPM. pH has no units.

 

[LGLDSR73]

Thank you both! Mknauss, what's your high temp today? One day last Summer you had 120°F.....

 

[mknauss]

The Easytouch got to 123F yesterday. Supposed to be the same today. Rest of week should cool to the 115 range.

 

[LGLDSR73]

OH GOOD LORD!

 

[JamesW]

Good morning,
Trying to better understand Parts Per Million. Is a FC of 8.6 read as 8.6ppm or am I way off base?
Thank you!
Lyman

Example:

A pool with 26,417 gallons (100,000 liters) contains 100,000,000 grams of water.

If you add 100 grams of chlorine gas, the water will contain 1 part per million of chlorine.

All readings are given in equivalent units.

Reading.....Units.

Chlorine...Chlorine gas

TA.............Calcium carbonate

Calcium....Calcium carbonate

CYA...........Cyanuric acid

Salt............Sodium chloride

Borate.......Boron.

It doesn’t matter what type of chlorine you add, it gets reported in units of chlorine gas to standardize the numbers.

For example, if you add 100 grams of 70% calcium hypochlorite, the chlorine will increase by 0.7 ppm.

That’s because the percentage of calcium hypochlorite is given in terms of chlorine gas equivalent, which makes it easier to figure out the effect.

70% calcium hypochlorite has the “equivalent” of 70% chlorine gas by weight.

Adding 100 grams of 70% calcium hypochlorite is equivalent to adding 70 grams of chlorine gas.

 

[LGLDSR73]

Example:

A pool with 26,417 gallons (100,000 liters) contains 100,000,000 grams of water.

If you add 100 grams of chlorine gas, the water will contain 1 part per million of chlorine.

All readings are given in equivalent units.

Reading.....Units.

Chlorine...Chlorine gas

TA.............Calcium carbonate

Calcium....Calcium carbonate

CYA...........Cyanuric acid

Salt............Sodium chloride

Borate.......Boron.

It doesn’t matter what type of chlorine you add, it gets reported in units of chlorine gas to standardize the numbers.

For example, if you add 100 grams of 70% calcium hypochlorite, the chlorine will increase by 0.7 ppm.

That’s because the percentage of calcium hypochlorite is given in terms of chlorine gas equivalent, which makes it easier to figure out the effect.

70% calcium hypochlorite has the “equivalent” of 70% chlorine gas by weight.

Adding 100 grams of 70% calcium hypochlorite is equivalent to adding 70 grams of chlorine gas.

Thank you, excellent information! Thanks for taking the time!
Best,
Lyman