How To Use Progressive Web App aka PWA On 420 Magazine Forum
Note: This feature may not be available in some browsers.
When the plant as about the same height as the cup. If you have small drain holes in the cups, the roots will poke out of them, and that's a good indicator as well.
Nice grow hommie keep it green and just wait till you get to flower everything is beautiful and all smiles...
make sure you do not let your plants sit in saucers with water in them or it will kill their roots. plants loosing cotyledon leaves is normal. what size pots are you using for your plants? it looks like your plants are ready to introduce 1/4 strength nutrients to them.