Just about any bloom enhancer will have enough P and K to keep your microherd happy.so you say epsom salt has a good amoun tof (P) in it. what about the (k) i use piranha and dutch master zone what is a good (k) for them
Of course there's some variation in the quality of bloom enhancers. I use the Bud Blood, Big Bud, Overdrive trio for my flowering schedule. All it takes is a little extra to keep the microbes fed and you don't have to worry about whether you're feeding your plants crap.
Hammerhead would probably be another good option for a bloom enhancer to feed them.