How much Superthrive for Phals?

[The Mutant]

So, my stinking bottle of Superthrive arrived today and I'm wondering how much of this I'm supposed to use per liter of water?

I'll use it to stimulate root growth on three Phals, one mini Phal with floppy leaves and not enough roots, one equestris keiki that will arrive tomorrow with only three roots (but otherwise I think it's in good condition, it looked healthy on the pictures), and my dying equestris aurea's basal keiki. So, I think I need to use it when watering these three as well as maybe when I mist the aurea since the keiki has no roots and the motherplant have almost none either.

So, how should I dilute it? 1ml per 4 liters? That's what is recommended for active development but does this apply to orchids too?

Grateful for advice, tips, and suggestions as always.