But I am not new to shrimp
In 2009-2010 when I was in the hobby (left for ten years), I kept yellow backs, cherries, black crystals and OEBT, and green babaulti.
My water was VERY hard then. The crystals did breed slowly but filled the tank within half a year.
I am a bit skeptical on some of the "knowledge". I know people in other countries keeping PRLs at almost 7.4-7.5 and having no issues.
There are many other factors to consider and hard to say what is what.
Same PH is not the same water, and even same hardness