Peters 20-20-20 for my nutrient
 

hey ron im using pea gravel as a medium with continuous watering during light operation. is this ok? also im using peter professional plant food 20-20-20 for my nutrient, please advise (tomato,pepper,assorted herbs)thanks t.j.o

No it ain't ok. They will start to die anytime now. Peter's does make hydroponic plant food but what you got their is for dirt. You can add some Magnesium Nitrate and some Epson salts to that and you might grow something but by using the most basic system you could use you would better off using real hydroponic plant food.