Theres no reason to have the light on before they germinate and starts to sprout but when they do you should give them light asap. Some people have the lights there from the beginning to help with heating and to be sure not to give them light asap when they sprout.

As hex2006 said, make sure not to over water the rockwool, I had read that was the easiest mistake to make and I did it anyways.. Keep them inside the dome for as long as you can and do not ever "flood" the bottom of the tray with water, the cubes will take up too much. In the dome you probably wont have to water them for many days, at least thats my experience.

Well after the first day (I soaked the Rockwool) I noticed the Rockwool was dry almost so I actually flooded the tray about half a inch. The water isn't enough to touch the Rockwool, but enough to cause moisture with the dome. I've noticed my lettuce a few are a inch already, tomatoes I can't see out of the Rockwool, I'm keeping the fan on, lights on, and heat is regulated to 78 at all times. Humidity is about 45% in the tent. So today is day 4 (planted Friday), I think if they keep going strong this Friday I would put some nuts in there. I'm hoping they don't outgrow that little tray, because I have no where to stick them but in a 5gallon DWC. I would like to let them get a bit bigger first with he roots. Thanks for the help hex and naken!

Don't worry too much, they're tough. I've had seedlings pressing up against the dome waiting to be transplanted. I sow seeds in moist rockwool and put them in a clear clamshell container, like you get at the deli. I park them under my grow light just because there's room there and as soon as they sprout they have light.

I know that some people moisten their rockwool with a very light nute solution and have good results. I've never bothered to do that and I always get good germination.

Usually when I see the beginnings of a second set of true leaves, I get a bucket ready.

Also, lately I've been sowing seeds in paper cups using Ocean Farm organic grow medium. I just let them grow under my MH light and they can get pretty big before you have to transplant them. When I say "big" I mean the size you would buy them at a nursery. So far I've done this with a bush bean, zucc, and peppers. I rinsed off the dirt, put them in a net cup in a bucket, and the roots took off. No shock.

Wow, that was longer than I intended. I'm taking after HVG. :)

Correction: Foxfarm Ocean Forest
http://www.amazon.com/dp/B007C9QKCO/ref=wl_it_dp_o_pd_nS_ttl?_encoding=UTF8&colid=1FNMOBSED35KD&coliid=IIKWX4W9I3VNE&psc=1

Yeah, getting close Mitch. Couple more paragraphs...

lettuce in the net pots don't look so well after sticking them in the DWC yesterday. I think i did it a little to earlier. The tomatoes in the tray are just now starting to grow. I don't know why my rock wool is so soaked i dipped it the day i put it in and few days later put maybe a 1/8 in the tray at the bottom. The water was maybe a 1/2 inch away from the rock wool, there is no way it kept the rock wool that soaked. I'm pretty sure i should of kept the lettuce in the tray until i could of transplanted to where the hydroton covered over the rock wool. I did my best to block any gaps so there is no light shinning through the net cups into the resivor.

Look who's back! LOL

never left lol

Secondly how am I get salt build up on the hydroton after a day lol, that doesn't seem right. PH was 6 and TDS 600ish when I turned it on yesterday.