The plants may have been potted up a bit too much. A gallon of Promix will easily support plants three times that size.
They still look good and should really take off when they get more roots established.
I did Promix with Foliage Pro in seven gallon bags this season and grew some decent sized plants.
I don't usually use liquid ferts, but I went to an estate sale and they said I could have all the stuff in the orchid
greenhouse for free. They were gonna have to pay to have it all disposed of anyway.
I switched back to Jacks321 for flower.