I don't know if they're yellowing from a lack of P or K, or a lockout. I'd feed less and see how they respond. They either want more or less Bloom food. You gotta be the judge. I'd do plain water for a bit and flush some of the salts out.
You can use molasses now. It's not some magic bud sweetener if that's what you're thinking. It's more to feed the microbes, and it has some K in it. Do you have any microbes you add?