Orchid Winter in Florida -- Mold/Fungus!?

[paphlovian]

Hello!

I am going through my first Florida "winter" since my orchid addiction started. I have brought my orchids in the house several times when it has gotten cold enough, but, I am trying to keep them outside best I can so they can get air circulation and sunlight. THE PROBLEM I've been encountering is a mold and/or fungus growing on the bottom of the clay pots and which I can see the same fluff in the bottom holes. (It smells like a mushroom). Also, some of the potting medium has areas of white on the top... it could be a build up of elements from the water, or possibly mold? I just don't know what I can do to "treat" this or stop this. Vinegar and baking soda? I don't want to kill my orchids and the potting medium has already been changed months ago (it's not yet time again). I'm trying to not overwater. I'm often not home until it's almost dark, so have been unfortunately watering a bit late than would be desirable. I know that's not good. If this mold growth continues, it might become a huge problem, right?

I wish I could include photos, but am still without the proper equipment to upload them! Sorry, I know how useful photos are!!!

Thanks for all your input!!! :-)