What should I be doing at this point?

Hey all. My first grow ever. I've got 6-7 plants that germinated. I started off wrong and this is what I have done so far.
Left the seeds in paper towel for like 5 days instead of two. Tap roots were really long. Put them in RW in aeroponic system. They are in a closet in a garage. Temps were around 100 degrees for the first two weeks of in the aeroponic system. Seems that the growth was really slow. I nute burned them once. Temps are now at 80 - 82 since I changed to CFL's and T5 light and growth has exploded instead of MH. They are (i think) 3.5 weeks old (only counting time in the aeroponic system).

PPM is at around 450-550. pH is at 5.8
They are getting 20 hours light, 4 hours darkness.
They are sprouting the 7th set of alternating leaves. Max fan leave count in 9 on a single off-shoot. I am also having fan leaf branches growing off of older branches.
The roots are approx 7 inches long.

My question is about how old are these plants? Why are some taller than others?
What PPM nutes should i be using? What light schedule should i be using at this point? How close should the lights be?
Can I tell if male or female yet at this point?

Thanks!

This may sound harsh, but you need to read one of the many MJ growing guides. MJ horticulture, the indoor/outdoor med growers bible is really good. If your totally poor its available by bit torrent.

You've done so many things "wrong" at this point, you need to build up your base knowledge of horticulture and MJ cultivation in general. Lest you grow them nice and big and watch them herm.

They look fine, even at 3 weeks. Keep doing what you're doing and make adjustments to get it dialed in.

Yes I realize I've done many things wrong but as a first grow I am just trying to see if I could successfully grow them. I've seen so many pics on here of people fking up their plants. J
ust getting my feet wet.