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.