well so far so good, hehehe...
you luuucky!
anyways, white rhino is or should be a very tough plant, very bullet proof compared to other types.
you now need to forget them for 2 weeks and just water when things dry up, dont worry about nutes until then. they should suck up everything the h2o is dilluting in the soil.
what you should do in the mean time, is buy some more lights. my WR grew fine during veg with 6-8 lights each plant. and about nutes what will you use.
just study. oh go to home depot and get thos socket spliters you will need a couple of them. STUDY