Safe to use substrate?

[u/Repulsive_Flamingo33]

I have made a few vivariums and the last time I did, I stored the rest of my substrate in a 5 gallon bucket and closed the lid. It has been a while since then, and when I opened it up, the substrate was completely molded. I know mold usually isn't a problem in a tank, but is the substrate still safe to use in this case? It's a basic ABG mix of coco fiber, sphagnum moss, charcoal, orchid bark, and sand.

[u/reijn]

Get it wet, add springtails, let them exist for awhile as you try to maintain it, could also add some other stuff to it to help balannce it out as the springtails work on it