Experiencing a bit of mold growth on some soil blocks I've made and have set up indoors. I made them using a homemade blocker (PVC Mold + Large Bolt, wood press, and a couple nuts) (the blocks are about 3" width x 3" depth). I wanted to start with bigger blocks so that I would not have to 'block-up' after some time. They are in a basement with temperature of 60° and about 45% humiditiy, steady.
The soil blocks were made with: Peat, perlite, organic potting soil mix, organic lime, organic fertilizer + water
I was starting some kale. It's been 5 full days since I made the blocks and added the seeds. This is the first day I've noticed the mold growth.
Yesterday was the first day I watered them since they were blocked - they were not THAT dry, I suppose. I misted them thoroughly from above and lightly from the bottom with the trays they are resting in (aluminum catering trays). I am guessing I may have been over-watering.
I have not had exposed them to lights for what would equivocate daytime, but I have ballasts hung (Using T5 & T12 6500K Fluorescent bulbs). I was waiting until something germinated to do this.
I have not turned on the fan that I planned to use for air circulation for them yet.
If anyone can share some perspective on what my mistakes are and what potential solutions are, that would be much appreciated.
I'm thinking cold + wet are my enemies here and I'm trying to think ahead to whether or not the fluorescent bulbs being lit over the plants is going to make any difference temperature wise, really. I'm also wondering if having the fan on would make much of a difference. I also had the thought that I might able to fabricate a wall of aluminum foil surrounding the trays that the plants are in AND put on the lights.
Someone suggested that my starting mix might not have been sterile and that I should microwave??? it before using it. I really don't know about that one.
Below's pictures of the blocks + mold.
Thanks for any input. It is sincerely appreciated.