Im going to buy some clones - what to look for and do next?

How long should it take for new roots to show up in these babies?

All 5 clones had at least some roots showing out the sides and/or bottom of the rock wool cubes, but after 6 days in the dixie cups of perlite, I can see no signs of new or growing roots. I have them in simi-clear cups that are inside a second cup wrapped with black tape - to keep light out. The tops are covered loosely with dark fabric to keep light from the tops of the cubes and roots. When I bottom feed them, I pop the inner cup out so I can look at the perlite to look for new root growth - but there is no sign so far.

The nutes Im feeding are Mega Crop at 5 gm/gal with the PH set to 6.05. The 5 gm/gal is the starting dose recommended for new seedlings. Im running the lights at 20 watts/sq ft set 24" above the plants.

The new growth leaves look good but they are not growing fast at all. There are still a bunch of sick looking older leaves, but I removed the really sick dead looking ones.