Calcium Hardness & Ice Melt

Winger 03

Well-known member
Sep 7, 2009
231
Frederick County, MD
Winter here on the east coast making it a great time ot pick up some ice melt to use to up the CH in my pool this spring.

Quick question - the ice melt I am seeing is a mixture of Calcium Chloride, Magnesium Chloride, and Sodium Chloride. Is this OK to use or should I seek all Calcium Chloride pellets?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,099
Tucson, AZ
Winter here on the east coast making it a great time ot pick up some ice melt to use to up the CH in my pool this spring.

Quick question - the ice melt I am seeing is a mixture of Calcium Chloride, Magnesium Chloride, and Sodium Chloride. Is this OK to use or should I seek all Calcium Chloride pellets?
You really want pure calcium chloride if possible. The other chlorides won’t do any harm but you’ll have to guesstimate a bit on the amount to add. Just make sure the stuff doesn’t contain a lot of dirt, some ice melts add sand to the mix to improve grip. You could predissolve it on a bucket first to see if any impurities settle out.
 

IMissNimoy

Gold Supporter
Jul 3, 2018
55
SC
I was going to suggest purchasing this but noticed the price has jumped significantly. I purchased the same for $24 in October '18. It's good clean stuff. I wonder why the dramatic jump?
 

Winger 03

Well-known member
Sep 7, 2009
231
Frederick County, MD
You really want pure calcium chloride if possible. The other chlorides won’t do any harm but you’ll have to guesstimate a bit on the amount to add. Just make sure the stuff doesn’t contain a lot of dirt, some ice melts add sand to the mix to improve grip. You could predissolve it on a bucket first to see if any impurities settle out.
Thanks Matt - so you are saying that the other chlorides will not increase the hardness at all but will do no harm - I guess that is OK in a pinch. I'll keep looking as I am about town.
 

jseyfert3

Bronze Supporter
Oct 20, 2017
476
South-Central WI
They do that mix because calcium chloride is expensive and most people won't want to buy it.

You should be able to find pure calcium chloride somewhere though, cause it has the lowest overall melting temp.

I maintain two buckets of ice melt at my house. Regular sodium chloride for temps above zero, and pure calcium chloride for when it goes lower and there's ice on walkways.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
16,099
Tucson, AZ
Thanks Matt - so you are saying that the other chlorides will not increase the hardness at all but will do no harm - I guess that is OK in a pinch. I'll keep looking as I am about town.
Magnesium will increase your GENERAL hardness number (magnesium + calcium hardness). But, because magnesium compounds don’t generally scale out of solution until the pH get really high, it doesn’t matter much. I wouldn’t call it totally benign but I wouldn’t lose sleep over it.