Hi jayc, thanks for the information, I noticed you replied on my earlier thread as well and I didn't thank you, so apologies for that.
Those parameters nearly fit with what I've got at the moment, although I probably need to bring my GH up, I'm using rainwater, but adding LCA shrimp additive.
TBH I suspect my reason that I lost shrimp early on was a few rookie mistakes. I read that they love biofilm and went overboard adding driftwood that had a tonne of biofilm but didn't realise that in excess it could suck all the oxygen out of the water. I'm only keeping one piece in the tank now.
In addition, i thought that because I was dosing seachem stability I could add shrimp earlier than I probably should have.
The ones in the tank remaining seem to be doing OK.