Hey KIG,
So if you're using a full cyco line you really may not need to add anything extra...especially if you're also using their potash plus.
I think if you are going to try to boost up your PK numbers I would go very mild and possibly apply 1/4 tsp per gallon once a week for weeks 5-8 of flowering. And only more if you think you're seeing any deficiencies from grow to flowering, at like 1/16 tsp.
Good luck friend, and always remember "Less is More"
😊😁