Contributed by Sportster:
Start with standard rockwool seedling cubes. Soak them in pH adjusted RO Water, and then get your seeds ready. You can
germinate them in paper towels, gauze, cheesecloth, or just do like me, and not fool with all that-- just poke the seed in the rockwool cube where the hole is pre-made. If you find that's too big for your seeds, turn the cube over and poke a smaller hole.
When you think your cubes have soaked up enough water, take them outside, or to the bathtub, and holding it loosely, give them 2 or 3 hardy shakes. (DO NOT SQUEEZE OUT!) This will release LOTS of water from the cube, thus making air pockets within the cube itself. These air pockets are very important for seedlings and clones. Also, by doing that, you keep your seed from soaking to death...too much moisture will kill the seedlings.
When you get the most of the water out, pick the seeds you want to grow and drop them in the hole about 1/4"-1/2" down. Carefuly squeeze the hole closed and place in a humidity dome. Light isn't all that important until the seed sprouts, however its very important to keep the temps around 80*f in your grow area. Warmth will speed up the process considerably as will a few drops of Superthrive per gallon of water.
Within 4 to 7 days (up to 14..) you should see seedlings poking out of the cube-- this is where I really watch whats happening as the TAP ROOT will grow faster than the plant itself. When this occurs, I get them ready to move to a 2 gallon rooter DWC bucket with 3" net pot holes. I will take the seedling, and place it in a 3" netpot with a few rocks on the bottom, as to support the cube, and leave plenty of space for the roots to grow without letting them lay on the bottom of the humidity dome's tray. I try to suspend the roots as long as they are in the dome. When I feel they are old enough (when there are a FEW small roots poking out of the RW cube) I will place the 3" pots with the seedlings in them, in the rooter bucket for about a week sometimes two if I am using fluorescents for vegging.
In that time, I will have a 5 gallon bucket ready, and I will carefuly try to weave as many of the roots thru the holes of a 6" net pot, and like with the 3"er, I will place a small amout of rock on the bottom of the pot to suspend the roots, and allow ample space for more roots. I place the 3" pot into the 6" pot and then fill up with rocks, finally covering the 3" pot (kind of like a BOG double pot method for soil) and placing that into the lid of the 5 gallon bucket.