what is ppm.. new here first post!

Hi, I have been ready and tried search for ppm but don't have any results.
I see on the charts 1ppm, 2ppm what is ppm?
TIA

parts per million

It's a measure of the concentration of something in the water.

On all but one test, we measure the results in PPM, part per million, and have recommended levels (sometimes based on other levels)

Chlorine:
FC(Free Chlorine): The good stuff that does the work. There's a min and a max level depending on how much stabilizer(CYA) you have. Then there's the "shock" level to kill anything growing and break down CCs.
CC(Combined Chloramines): Sometimes called Combined Chlorine but that's not accurate. Used-up chlorine that gives the classic "disinfectant" odor, and irritates eyes and skin. We blame ALL chlorine for its faults. We burn it out by adding MORE chlorine and "shocking" the pool.
TC(Total Chlorine): Usually, in most little OTO or DPD kits this is what you test for. TC = FC + CC always. If something indicates this is not true, you are doing something wrong.

Total Alkalinity:
Also called Alk, T/A, Tot. Alk., TA.
This is a buffer for pH that keeps pH from bouncing around. We normally recommed a level of 80ppm to 125ppm, but in vinyl pools the upper limit is 180ppm. Raise T/A by adding baking soda.

Stabilizer or CYA:
Also called Isocyanuric Acid, or Cyanuric Acid, or Conditioner.
This prevents rapid breakdown of chlorine. Too little is bad, too much is bad. We recommend 30ppm to 50ppm

Calcium Hardness:
Also called CH, Hardness, Ca, or Calcium.
ONLY useful for concrete, gunite, tile and some fiberglass pools (to avoid voiding their warranties. Absolutely UN-necessary on vinyl pool
We recommend levels of 200ppm to 400ppm unless you have vinyl or most fiberglass pools, in which case you can go from 0ppm to 500ppm. That is, you don't want too much.

pH:
This is the only test that isn't concerned with parts per million. It's a measure of acidiy. We prefer a range of 7.3-7.8. You can raise pH with ordinary 20 Mule Team Borax, or Soda Ash, sold by Arm&Hammer as Washing Soda (NOT baking soda!). Soda Ash also raises total Alk. Lower pH with Muriatic Acid or Dry Acid.

Carl -

You should add this as a *Sticky* - it is difficult for new people to pick out all the acronyms.