If I put tap water into a butt or can, and leave it say for a week, is it closer to rainwater? I'm thinking in terms of ph for watering my ericaeous pots, plus my Slightly acid garden soil.
I can't see standing could remove calcium from water. Evaporation would concentrate it a bit more if anything.
That tap water chlorine smell would go.
I Have camellias in pots and give them a mix of rainwater and tap water. Sometimes one, sometimes the other. Probably 2:1 rain/tap. Also use sequestrene to help the plant take up nutrients which helps overcome any deleterious effects of tapwater. I live in a hard water area. If you live in a soft water area you are probably OK anyway.
Most important is to water , particularly in late summer/autumn as they form the flowers for next year. Letting them dry out is always a problem.
The colour of the leaves give you a clue as to how happy they are. Dark green signals happiness. Yellowing leaves and is time to give them feed/sequestrene and rainwater. Do this and they will recover.
Alan, why do you use Jeyes Fluid in your water butts? There has been a thread about this before, and if you keep your water butts well-covered, they never need washing out, and certainly not with Jeyes Fluid.
Alan- do you sing that song when you clean them out?
"I like big butts and I cannot lie...."