calcium hardness

[goneaway]

Is there a formula for calcium hardness ?
Im trying to reduce foaming and chem geek recommends checking the calcium hardness.
My local water authority suggests that my water is around 100 on the hardness scale.
Chem geek i think suggested around 150.
Without buying a test kit.  How much calcium chloride would i need to 350 gallons?

[TwinCitiesHotSpring]

personally I wouldn't add any Calcium if your at 100ppm...that number is perfectly acceptable, but just as an FYI the calcium booster we carry states @ 500 gallons, 1oz. will increase calcium hardness by 7 ppm

[chem geek]

For reducing foaming, 120-150 ppm is an amount of CH that works, but 100 may also be perfectly acceptable.  It all depends on how much foaming you have (and there are other ways of preventing it as well).

You absolutely should not add calcium chloride without knowing your current CH level.  You should have a proper test kit (preferably the Taylor K-2006 if you are using chlorine).  If you increase CH without knowing your water's current CH level, you can cause scaling by getting the CH too high.  The Pool Calculator can be used to calculate dosing.

[goneaway]

Hi CG.
I'm currently using Bromine, however, will probably be switching back to Chlorine when the Bromine stocks have depleted. test the water direct from the source, or after the chemicals have been added ?

Despite both of us showering before we jump in the tub, and both costumes having only been rinsed in fresh water, foaming starts after about two weeks.
Usually very slight to start with, and if i'm being honest, it's usually then when I start tinkering, so potentially making it worse.
Last week (2 week old water), I added Aqua Sparkle and made it almost like a bubble bath.
So decided to change it again.

According to my water authority, my calcium hardness peaks at 103 mg/l, with magnesium at 9.6mg/l, and overall average of 117mg/l.

[chem geek]

So long as you don't add calcium chloride or use Cal-Hypo (normally not used in spas), then your CH should not change except from some evaporation and refill.  So I wouldn't raise the CH above around 150 ppm in order to prevent scaling, especially in the heat exchanger.