Outta curiousity, mouse, why do you foliar feed small plants ? The only time I've done it is to prove to some brother growers that they have a particular nutrient problem. Oh, and I use sometimes on clones if the leaves start yellowing while developing roots.You could I guess it wouldnt do any harm at this time. I usually foliar small plants with a mild rhizotonic solution. Works good for me. I use Magic green on vegging plants and HALO on flowering ones.
I still have this nagging thing in my head that says its nutrient or dirt related. Give them like 1 CFL and no Co2 for a few days and see if they perk up ?
Just keeping the ideas flowing....
Mouse