That actually sounds very promising - high pH/GH/KH should be a better situation than a bit of salt for them. All that good calcium and magnesium (shells need this) and the carbonates/bicarbonates to match.
Yep, I noticed that their shells don't have the scarring like mine do either. Maybe I'll throw all mine in my Endler tank and gradually bump the levels up.
My plant tag is offically AWOL, but I *think* the levels were about like this: pH 7.6, GH 16, KH 12 temp around 72-74
Hmmm - I had not thought that much about lower temperature paired with harder water. Now there is an easy to test idea. Perhaps part of the breeding block is just tropical temperatures. Excellent info Dapple2. I really appreciate it.
Things like breeding seasons in the wild are so easy to overlook in our highly stable heated/AC'd houses.
Why do I always want/need more tanks? It is definitely a disease or pathology or addiction.
My few "cool" tanks have Taiwanese and Japanese shrimps, for better breeding. It could well help for the Nerites. Grow/condition them a bit warmer, then drop the temp for a season. I have to note that where I won't lose or forget it. It is certainly worth a try.