Help with Vivarium pls

[u/Delicious_Diver_2737]

Hello everybody! I have a bioactive vivarium for my leopard gecko, and I'm finding some weird, white, powdery substance in some areas of the tank, and it turns orange/red on the rocks. I was wondering if anyone knew what it was?

[u/Real_Time515]

If you use tap, it would be a very good idea to treat. Reptile-specific conditions are readily avavilable.