Raise calcium hardness... Calcium Chloride... use ice melt?

[IanMcLoud]

Using my Taylor 2106 test kit and instructions found on here (thanks @waterbear) I have gotten all my parameters in order for my Evolution Monarch 480 gallon hot tub from Costco... Except the calcium hardness, which seems to be testing at only 30 ppm (I live at elevation in the mountains of central oregon and it seems this is the expected value, I'm on well water near the city of Bend).

What is the best way to raise calcium hardness to 150-400ppm? Calcium chloride seems to be the answer... but using bottles of Leisure Time tub calcium booster seems like it will be an expensive and bulky proposition (that's basically a whole bottle for one hot tub fill!).

Google is telling me that calcium chloride is also the chemical compound of the ice melt for my driveway... so can I use that? Is there a better way?

Thanks!

[JWM6687]

I have similar levels of calcium hardness from my source water.  I use pure calcium chloride I sourced from Amazon. The 25 lb tub will probably last me a decade with my 300 gallon tub.

https://www.amazon.com/Pool-Mate-1-2825-Increaser-Swimming/dp/B00J7L46FI/ref=sxin_16_ac_d_mf_br?ac_md=2-1-UG9vbCBNYXRl-ac_d_mf_br_br&content-id=amzn1.sym.66ee1041-127b-4baf-8390-1a597387172e%3Aamzn1.sym.66ee1041-127b-4baf-8390-1a597387172e&crid=1YFY0TW8CM63O&cv_ct_cx=calcium%2Bchloride%2Bpool&keywords=calcium%2Bchloride%2Bpool&pd_rd_i=B00J7L46FI&pd_rd_r=87f946f0-2101-44d9-a34f-e84c51d79253&pd_rd_w=ZvUZv&pd_rd_wg=kQPcj&pf_rd_p=66ee1041-127b-4baf-8390-1a597387172e&pf_rd_r=CNY22B1XE2HZ439NPZBX&qid=1663077087&sprefix=calcium%2Bchl%2Caps%2C86&sr=1-2-4c1442dc-e644-4a05-a0d0-ff1b45d55b2f&th=1

I tried the Leisure time liquid, and was very dissatisfied with it.  If you read the fine print there is a range in the percentage of calcium chloride in it, thus making it impossible to accurately raise your hardness levels.  I had to use twice as much as the instructions on the bottle indicated. The pure calcium chloride was far easier to work with. 

You should double check the MSDS to find the chemical composition of your ice melt.  A lot of those are "blends" containing other chemicals you wouldn't want in your tub.

Happy tubbing 🙂.

[IanMcLoud]

YES! Thaaaaank you! (Yeah, I didn't want to put ice melt in my tub

[waterbear]

Some ice melters are ok, most are not. Pure calcium chloride in a 50 lb bag (food grade is not necessary, 77% - 80% is what is normally sold for swimming pools)  from an online chemical retailer or pool store  (online or brick and mortar) that also caters to pool service pros is your most economical option. Be aware that the dosing is different for the dihydrate and the anhydrous forms with the latter being more concentrated.  Either way, one bag will last a very long time.