i dont' think it's just Calcium, i think it's multiple non water soluble compounds that just happen to be white.
silicon dioxide, magnesium carbonate and iron ammonium citrate.
it dont think it's fungus, i dont see any
hyphae:
plural noun:
hyphae
- each of the branching filaments that make up the mycelium of a fungus.
you don't see any tiny hairs typical with a fungus colony growing.
if this is true then im not replying anymore, just gonna possibly ruin my reputation for something we can't prove anymore.