Can I Grow My Pot Plants in Clear Plastic Cups?

Dear Dan,
I transplanted some clones into clear plastic cups using Happy Frog potting soil and Plant Success Granular to maximize root growth. It’s been a couple days, and I have watered them as needed. I noticed today though around the root ball, there appears to be a green moss or a fungus. Do you have any idea what this is and what I might be able to do to get rid of it, if need be. Thank you very much. — Hans

Dear Hans,
The green fungus that you see is algae that has grown in your container, due to the fact that you used clear plastic cups. The cups allow light to reach your wet medium, creating the perfect area for the mossy mess to begin competing with your plants for nutrients and creating a breeding ground for pests and harmful molds. Transplant your clones immediately into larger opaque containers with plenty of soil mix and avoid harming your medium with fungus that isn’t beneficial and can be quite harmful to boot.