CH importance in a spa ?

[Brian VT]

I just refilled my tub and I used softened water this time because I wanted to try having some salt in my water and I figured that was the easiest way. I guess I could have crushed up softener salt and added that to the spa instead.
The softener removes most of the calcium from the water.
I understand that some pools need calcium in the water to prevent it from taking it from the pool shell.
Do I need calcium in my spa water even though the spa has a plastic shell?

 

[YippeeSkippy]

Some folks get a bit of foaming in their water and some calcium added helps that.

 

[pooldv]

CH between 100 and 150 is good. More here, How do I use Chlorine in my Spa (or pool)?

 

[Brian VT]

I assumed I had zero CH and I added 7.5 oz. of (old) Balance Pak 300 to my 350 gal.
I added 5 drops of (HTH) indicator to a sample and it's supposed to turn the water red if there's any hardness. It doesn't.
Do you think the indicator is at fault or the Balance Pak 300 or...?

 

[pooldv]

It is probably the test. Adding 7.5 oz of calcium chloride or calcium chloride dihydrate will add 109 ppm to 350 gallons. Even if it is old it should not degrade. Should be good to go on CH.

 

[Brian VT]

It is probably the test.

Thanks. I do have a Taylor kit on the way. Hopefully I can sort it out with that.

 

[pooldv]

Good plan!