1) the reason so many sources have so many varying parameters is because shrimp can be fairly adaptable. If you’re looking at breeder and retailer websites the values they show will likely be the parameters in their tanks. Caridina like softer more acidic water than neos universally but you’ll find numerous stories about different genus adapting to the parameters of the other over the course of multiple generations. (Don’t ask me how you get them to breed in less than ideal parameters, I’m not a pro by any means)
2) definitely don’t use that pH value variation as an acceptable range. If you do a bit of research into pH, you’ll find that the values are what’s called “logarithmic”. Now I got a C in dummy math in college but basically it means that a pH of 6 is 10x more acidic than a pH of 7. So a 1 point swing is a huge difference that could easily kill shrimp.
Glad to hear you’re doing your research so far in advance! Best advice I can provide is chasing parameters is always a recipe for disaster. You have 2 tried and true options. First is measure your tap water and find animals that will thrive in that environment. Second you can invest in an RODI filter and then just make the water whatever you want it to be by using shrimp minerals to remineralize. There are RODI kits that can be got on Amazon for like 100 bucks if you don’t need a large volume of water, mine is working great for my 12 gallon tank, fills a 5 gallon bucket in just a couple hours
Ok-Community-5247 
I’m interested in others opinions on this too, as I found websites confusion as you… none shows the same numbers
Couple of things spring to mind.
1) the reason so many sources have so many varying parameters is because shrimp can be fairly adaptable. If you’re looking at breeder and retailer websites the values they show will likely be the parameters in their tanks. Caridina like softer more acidic water than neos universally but you’ll find numerous stories about different genus adapting to the parameters of the other over the course of multiple generations. (Don’t ask me how you get them to breed in less than ideal parameters, I’m not a pro by any means)
2) definitely don’t use that pH value variation as an acceptable range. If you do a bit of research into pH, you’ll find that the values are what’s called “logarithmic”. Now I got a C in dummy math in college but basically it means that a pH of 6 is 10x more acidic than a pH of 7. So a 1 point swing is a huge difference that could easily kill shrimp.
Glad to hear you’re doing your research so far in advance! Best advice I can provide is chasing parameters is always a recipe for disaster. You have 2 tried and true options. First is measure your tap water and find animals that will thrive in that environment. Second you can invest in an RODI filter and then just make the water whatever you want it to be by using shrimp minerals to remineralize. There are RODI kits that can be got on Amazon for like 100 bucks if you don’t need a large volume of water, mine is working great for my 12 gallon tank, fills a 5 gallon bucket in just a couple hours