New Pool Owner - Testing Myself

[Newdude]

So it's Rocksalt, iron, magnesium, sulfates and some others.

 

[Gary Davis]

I don't like the 94% pure. There can be alot of devil in those details. It might be rock salt, it might be iron.

As you mentioned, there are a variety of "strengths" of calcium chloride on the market and we all are worried at first about the mystery missing percentage.
Types of Calcium Chloride

"I see on pool math there are two types of Calcium Chloride. One being Dihydrate and the other I assume is Anhydrous."​

Calcium Chloride Concentrations​

"Commercial dry Calcium Chloride Concentrations are 74%, 77% (dihydrate), 83-85%, 88-90%, and 94-96% (anhydrous)."​

So it's Rocksalt, iron, magnesium, sulfates and some others.

That's a great find of what that mystery ~6 percent is comprised of (actually it was a mystery 3%, almost all of which is table salt).

• Product name = Calcium Chloride 94% anhydrous CAS 10043-52-4
• CaCl2 purity = 94% minimum (result 95.6)
• Ca(OH)2 alkalinity = 0.25% max (result 0.13%)
• NaCl alkali chloride = 5% max (result 2.8%)
• Insoluble H2O = 0.25% max (result 0.02%)
• Fe = 0.006% max (result 0.002%)
• MgCl2 = 0.5% max (result 0.25%)
• CaSO4 = 0.5% max (result 0.03%)
• pH = 7.5 to 11.0 (result 8.8)

Nominally it's 6.5% pot luck ingredients, but in actuality, according to the numbers you unearthed, it's 3% mystery ingredients, mostly table salt.

• Nominal: 0.25% + 5% + 0.25% + 0.006 + %0.5% + 0.5% = 6.506% (with sig figs, that's 6%, most of which is table salt)
• Result: 0.13% + 2.8% + 0.02% + 0.002 + %0.25% + 0.03% =3.232% (with sig figs, that's 3%, most of which is table salt)

As for dosing calculations the percentage is multiplied by about 90% (where that 0.9018 is taken care of automatically in pool math) as Richard Falk explained.

• 25 pounds of 94% by weight of calcium chloride x 100.0869 g/mole CaCO3 / 110.98 g/mole CaCl = 21.2 pounds effective calcium (is that math correct?)
  • 25 pounds of 97% by weight of calcium chloride x 100.0869 g/mole CaCO3 / 110.98 g/mole CaCl = 21.9 pounds effective calcium (is that math correct?)
• 25 pounds of 100% by weight of calcium chloride x 100.0869 g/mole CaCO3 / 110.98 g/mole CaCl = 22.6 pounds effective calcium (is that math correct?)

Plus, SnowJoe is sold out this moment on amazon with an unknown resupply date.

I bought mine in the summer for about a dollar a pound for the 94% calcium chloride shipped to my door.
There's always the discussion of what type of calcium chloride it is though.

• 25 pounds of 94% calcium chloride at about $25 and at 21.2 effective pounds of calcium is about $1.18 per pound of calcium (plus a pinch of salt)
  • 25 pounds of 97% calcium chloride at about $25 and at 21.9 effective pounds of calcium is about $1.14 per pound of calcium (plus a pinch of salt)
• 25 pounds of 100% calcium chloride at about $50 and at 22.6 effective pounds of calcium is about $2.21 per pound of calcium (sans the added salt)

calcium chloride vs calcium chloride dihydrate​

I like puritech. It's a few bucks more

For about two dollars a pound for that Puritech 100% calcium chloride it's twice as expensive, but it doesn't have the 3% to 6% mystery ingredients my shipment had (which appears to be mostly table salt with a pinch of magnesium chloride).

I must admit though that I've always been confused by calcium chloride concentrations because I don't have the Richard Falk math figured out for calcium chloride yet. If you have the math figured out such that we can compare the effective dosage in our head like we can for chlorine, please let me know!

 

[Newdude]

I must admit though that I've always been confused by calcium chloride concentrations because I don't have the Richard Falk math figured out for calcium chloride yet. If you have the math figured out such that we can compare the effective dosage in our head like we can for chlorine, please let me know!

I must admit that I'm fairly calcium illiterate with a vinyl pool.

 

[Newdude]

*also worth noting, both salt and CYA are available in less than 100% concentrations. It doesn't mean they have to have undesirable additions to them. But it certainly means they might. Or that they didn't last time, but next time is another gamble. I personally will not buy any of the 3 that aren't 100%, for one less thing to need to think about.