What temperature and humidity levels should I be aiming for with my seedlings? I have 10 tiny sprouts in a propagation tray with a heating pad and humidity dome under a 400w metal halide light. They are only about 48 hours old and I'm wondering how to tweak their growing environment for optimum growth over the next couple of weeks. Thanks!
They're sponges called Perfect Starts. I got them as part of a propagation kit at an online hydro shop. They're supposedly easier to use than rockwool... no 24 hour presoak or ph adjustment required. I dropped 10 ungerminated seeds in and they all sprouted within 36 hours... some were poking through after about 20. This is my first grow, so I have no actual experience with rockwool or any other rooting medium... but this seems to be an easy way to start... so far, so good.
I tried using some different plugs from my local shop and they didn't work out. They looked really nice but some of the plugs dried in like 12 hours and shrunk, others stayed perpetually soaking wet. One thing that confused me was how to handle lighting. Because the little seed holes aren't covered I kept them in the dark too long and they got a bad (stretched) start. Did you start out with lights on or off? Did you have problems with the plug dampness like I did?