Pool Math - Effects of Adding Chemicals calc not same as Now/Target

[IrwinK]

First time using Pool Math. For PH entered my Now reading of 8.2 and my Goal is 7.8
Says add 22oz of 31.45 muriatic acid.

When I enter on bottom of page 22oz. says it will l lower PH by .35
These don't agree but not by much.

Are these rounding errors or am I doing something wrong?

 

[pabeader]

Looking at the number of decimal places, I would say that .35 and .4 are the almost the same thing... since that's what you get when you round up.

 

[JoyfulNoise]

Look at the warning note in the Effects section. It clearly says that the pH calculations are approximate because it has to make certain assumptions about other values in order to do the calculations.

 

[pooldv]

Correct. PH is impacted by many factors, TA, borates, etc. The more info entered into Poolmath the more accurate the calculation.

 

[IrwinK]

Thanks everyone. I thought it might be the rounding but didn't know about the other factors that can affect it. I haven't entered all of those yet.

Tomorrow is my start-up day with the PB. Pool is filled with tap water.

 

[pooldv]

Nice! Be sure to follow your installer's instructions, the mfg instructions and register your warranty, more here, Wet Edge | Warranty Wet Edge | Warranty. The first 30-60 days are important.