I actually use ph test strips and not the meter.
If your membrane is that bad that you have to use a acid wash than yes you should wait 24 hours.
Personally I have never used a acid wash on the membranes that I used.
It is getting more popular to use a small evaporator with a large RO.
You usually lose up to 20 percent or so total volume as it gets real sweet. less water to be taken out.
I always just use the soap that Lapierre sells.
We are usually running 400-450 when it is at 24 %
This is what I do, it certainly doesn't mean that everyone does this.
Success is not final,failure is not fatal.It is courage to continue that really counts
“I have not failed. I’ve just found 10,000 ways that won’t work.”
– Thomas Edison