Welcome to the worst place to be on our knowledge base. You are probably wondering if your kit is contaminated.
Your kit is getting to the fruiting stage and you start to see white mold coming out. There are 2 types of white mold. One of them is a good mold coming from the magic mycelium itself. See fluffyness on substrate for more info.
Good white mould
If this is what your kit looks like then that is a good sign, it is the start of the fruiting stage.
Is your kit not growing? Click here and read more about what to do when you're kit is not growing!
Bad white mould
Then there is the other type which is called Trichoderma Tarzianum. which looks like this:
When the Trichoderma Tarzianum got into your grow kit it will show up as a small white spot and start to spread out rapidly. Usually, it will take over your complete kit in a matter of one or 2 days. The white mold will cause soft rotting of the substrate and will start producing spores of their own which are green of color.
Bad Green Mould
If a Trichoderma harzianum contaminated your kit it is unfortunately lost.