No Veggi , I use strictly the Happy Frog soil itself in 4 inchers.....worked great and all sorts of beneficial things in both soils.....another plus. Same with FFOF....no additions; just good tap water at correct ph for soil (about 6.5) and so far its been great. I WAS doing what White R here was doing.......watering too much and just flooding things out and leaving the soil too wet at the same time so I think the problem isa little of both of that in this situation.
I DO use a product called rhizotonic for my roots but its fairly expensive and not a necessary with a quality soil like HF or FFOF imo.
