Water Chemistry

[Lower Case T]

Hey forumites,

Randi and the good Dr. were in the pub today. we started talking a bit about water chemistry and found out we were all three confused on how to read the water report and apply it to spread sheets like John Palmer's.

I had made the mistake a long time ago of reading the Ca and Mg numbers as is from the water report (i've attached July's). Let say it says 61 under the Ca column. Well that 61 is actually Ca parts out of CaCO3. So its a lot higher than the actual number you need to be using.

I've attached a couple parts of some email conversations I had with a friend at the water plant and John Palmer. The first part is from a while ago when I asked Mark (chemist at CR plant) for the second time how to calculate it and then just a few months ago I asked John Palmer for some help. He noticed that I was using those wrong numbers (AGAIN).

So I thought everyone might want to take a look. If you have more questions about the context of the conversations let me know. If you have more questions about water chemistry...... yeah. I got nothin there.

[tompb]

Hell I got enough trouble trying to make beer. I'm not sure if I'm ready to try making water.

[carrisr]

OK I think I understand the difference now. It turns out the numbers on my report are already in parts per million so I don't need to convert them. So if you are going off of a report from Ward Labs, you can go ahead and use the numbers as is, but if you are using the CR water report you need to convert to ppm first.

For those of you who may be looking at a different report and you are not sure which format your Ca and Mg are in: if it lists all values as ppm chances are you are go to go. If it lists them grouped in "Hardness as CaCO3" you will need to divide the Ca by 2.5 and the Mg by 4.12.

****WARNING: Major geekyness ahead. Skip this if you are not a geek and DO NOT want your brain to EXPLODE!!!*****

You can double-check this with the following formula from Palmer's book:
(Ca/20 + Mg/12.1) * 50 = Total Hardness as CaCO3.

So from my water report: Ca=90, Mg=39, Total Hardness=388
(90/20 + 39/12.1) * 50= 386
I'm sure the Ca and Mg numbers are rounded which is why there's a 2 point discrepancy.

If you look at the average water numbers (J Ave) from the report Travis provided, and used the Ca and Mg numbers as is (Ca=58, Mg=64, TH=122) you should have a total hardness of 409 instead of the stated 122. However, if you do the conversion above first (Ca=23, Mg=16) you get 123.6. Which is again is right where it should be.

Wow, I think my brain is overheating! I wish I remembered more from Chemistry 101.