I've got two seedling right now, others haven't sprouted yet, and they are only 1.5 - 2 days old, and I see a little root about 1cm long sticking out the bottom of the rockwool for each of the seedlings two questions. 1. when should I transfer them into my hydroponic setup? 2. should I transfer the 1.5" cubes into the 3" cubes before I do that or would/should I need to do that at all?
What kind of hydroponic setup are you using? I've germinated plants with the paper towel method and just dropped them straight into a hydro setup (perlite/verm bucket) as soon as the root popped.
No, don't transplant them into bigger rockwool cubes, you want to keep the rockwool away from the misting from the bubbles because rockwool will saturate and cause root rot. Transplant when there is a good nest of roots under the cube, this way it won't take long for the roots to grow through your net pots. Put around 3 rows of pellets (hydroton) in the bottlom of your net pot, then place the cube/seedling in and fill around and on top of the cube. You want to block as much light from the rockwool cube as possible to help stop fungi grow on it. When you have transplanted, only water the outside pellets with only ph 5.8 water, until the roots show thru the net pot (this should only take a day or so for the roots to appear thru). Watering the outside pellets (closest to the wall of the net pot) will make the roots search for water/nutrients and not water log the rockwool cube, cutting off the oxygen supply to the roots. If you water the pellets with a nutrient solution, fungi will grow on the pellets, it wont do the seedlings any harm watering them with just plain pH water for a day or so.