The salvia are being repotted into the same free draining and lightweight mix as the cacti are going into:
2 part coconut coir
1 part turface
1 part hydroton 4-8 mm spheres
The salvia have adapted. After one day of the leaves drooping, they are perky and upright.
It was amazing how much the roots had packed the old soil tight thus restrcting water drainage and aeration.
I did check on the coconut coir - it is slightly acidic - pH = 6.2, but it has a very low salt content. 2 quarts of the coir were washed and the washings collected and evaporated to dryness. Nothing but brown lignin-like materials.
How has the new soil been working for you?