pk boosters

I was curious to know if anyone knows of or has any experience using pk boosters for hydro? I'm growing dwc and noticed my plants demands are increasing. I may need to add a supplement for P and K just not sure which is good for hydroponics. Thanks in advance for the help!

Day 35 of flower these ladies are looking frosty and gorgeous . I've had to bamboo stake both the slurricane's from how much weight they have put on . Pulled one of them out of the tent today to water and it literally started to fall over sideways lol. 3x3 Grow tent Ocean Forest Soil Fox Farms...