I’ve recently inherited a very healthy Zamioculcas Zamiifolia ( a.k.a. ZZ Plant ). It’s in a deep 5-1/2inch plastic pot. Roots are not in soil. Growing medium are light weight pebbles resembling coco puffs. I want to repot to a slightly larger clay pot. Shall I repot with more of the same pebbles or switch to a gritty well drained soilless mix. What are these pebbles called and where do I get more. Roots on this plant, I think resemble Orchid roots.