guys; that green is algae, so you could be introducing algae to your room when you transplant. perhaps from now on, you might cover the top.
As far as clear containers, you should use dark/opaque containers to keep algae from starting on roots.

light x algae = root problems/lower yielding plants
consider this, once algae is introduced you can only control it, you can't make it go away completly without killing plants.

for algae control, fountec or hth algaecide 30.
2 drops per gallon initally, then 1 drop per gallon for weekly
maintenance, goodluck.lw
latewood Reviewed by latewood on . roots in perlite I'm really pleased with the results I got from rooting clones in perlite and planting seeds in it too. The clones never wilt and I don't use cloning gel or humidity dome or even spray with water anymore. Rating: 5