Did pH with liquid indicator and it looks like 6.8 or so. Whatever it is doesn't look to be spreading.

In any case, they are due for repotting in bigger pots. I actually already have some perlite as well as horticultural vermiculite from a previous project. You guys recommend using just the perlite or both, and what ratio? 2/3 MGO & 1/3 perlite or 2/3 MGO 1/6 Perlite 1/6 Vermiculite is sort of what I've gathered.