Problems with my softwater shrimp

So I have been having problems with all my softwater shrimp with the exception of my Golden Bees with have FINALLY started breeding for me.   Upon suggestion from Bill Southern I tested the pH.  All the tanks I was having problems with had a pH of 7.5 or higher despite using Aquasoil and 100% RO water.  It seems the Aquasoil no longer wants to buffer my water.  I have tried using Muric Acid (HCI) to lower the pH but it keeps wanting to creep back up after 12-24hrs.