I started a bunch of seeds in rockwool and transferred them to red party cups filled with perlite as soon as they sprouted. I am feeding them with a weak fertilizer and have them under some cool white fluorescent lights. The plants are getting droopy and yellow and refuse to grow. Do you know what’s wrong?
One-hundred percent perlite is a poor choice of growth medium. The young plants are not getting the proper levels of water and oxygen. You need to immediately transfer them to a soil or hydroponic system to save them. Perlite makes a wonderful amendment to soil mixes and I use it every time, but as a standalone medium it pretty much sucks. The one exception to this would be a small hydroponic system, but even then the light weight of the perlite creates some stability problems.
Act quickly and you can save your crop!