Calcium Chloride

Duberz · Feb 11, 2016

I'm looking into making my own two part. The problem is I live in Florida and can't seem to find it. I know I can get it from brs but I'd like to find it locally. Anyone live in Florida who has found it?

Randy Holmes-Farley · Feb 12, 2016

Some people use calcium chloride they get from pool stores. I think Leslie's is a popular brand to use, but I've not tested it.

Duberz · Feb 12, 2016

Thanks Randy...if I can find that would it be the same amount to use in your recipe as dowflake 77-80?

Randy Holmes-Farley · Feb 12, 2016

Yes.

beaslbob · Feb 12, 2016

you could also try redimix concrete places. The use calcium chloride to speed hardening at cooler temperatures. One place here years ago even had dow flake.

redfishbluefish · Feb 12, 2016

Randy @Randy Holmes-Farley , if I'm not mistaken, the Leslie's calcium chloride (Hardness Plus), is anhydrous (94-97%), while DowFlake is not (77-80%). Accordingly, as you state in your recipe about using anhydrous, you'll want to use 20% less. That is, 2 cups of anhydrous calcium chloride to a gallon of RO/DI water. Take note that this will get fairly warm when dissolving.

Robthorn · Feb 12, 2016

Duberz, what part of Florida? There are several places in Tampa you can get this stuff from. Kalk, mag or whatever.

Randy Holmes-Farley · Feb 12, 2016

redfishbluefish said:
Randy @Randy Holmes-Farley , if I'm not mistaken, the Leslie's calcium chloride (Hardness Plus), is anhydrous (94-97%), while DowFlake is not (77-80%). Accordingly, as you state in your recipe about using anhydrous, you'll want to use 20% less. That is, 2 cups of anhydrous calcium chloride to a gallon of RO/DI water. Take note that this will get fairly warm when dissolving.

It may be.

I was just going off the info on their web site which works out to 73% calcium chloride:

http://www.lesliespool.com/leslies-hardness-plus-pool-chemical/hardness-plus.htm

Dosage: 1.25 lbs per 10,000 gallons
Pool Chemical Features

Calcium hardness increaser
Keeps your pool and equipment free from damage
Increases calcium hardness by 10 ppm per 1-1/4 lbs.

My calculations:

1.25 pounds = 567.5 grams
10,000 gallons = 37,850 liters

anhydrous calcium chloride is 36.1% calcium

So 567.5 grams has 205 grams of calcium,
and
205 grams of calcium is 512 grams of calcium carbonate equivalents

So the Leslie recipe would give a boost to calcium hardness (in ppm calcium carbonate equivalents) of
512 grams per 37850 l = 13.52 mg/L = 13.52 ppm

The only way that can work out to 10 ppm is if the product is only 74% calcium chloride.

redfishbluefish · Feb 12, 2016

Most interesting Randy! I went off their MSDS HERE, which states 94-97% calcium chloride.

I can't argue with your math, but which one is it???

mcarroll · Feb 12, 2016

Taken for what they are, there are comments on the Leslie's page indicating there are at least one or two folks out there mixing two-part with it at the 2 cups/gallon ratio.

Does make me wonder...are the instructions on the product (1.25#/10K gal) wrong? Is everyone wrong?

I do think the MSDS is referring more to the class of material than the tested parameters of the stuff in the package....but 94% vs 74% is a rather large disparity!

I don't think this helps with Leslie's instructions, or maybe anything else....but left exposed over time, won't anhydrous become more and more "hydrous" and therefor heavy? ...causing more and more grams of material to need to be mixed to get the same Ca level?

It sure seemed that way with my last big bucket of Ca like this...I had to make two adjustments to the mix formula over the time it took me to use up the whole bucket. (2-3 years, if I recall correctly).

Randy Holmes-Farley · Feb 12, 2016

I think Jim Welsh may use it. Perhaps he or someone else can tell us which it is based on heat released, and which exact product since they might change it over time and not update some of these online resources.
@JimWelsh