best and easiest way to cure a nitrogen deficiency

three of my plants are light green and have stunted growth and the deficiency charts shows that its a nitrogen deficiency.

i dont know mush about nutes cuz ive been growing organic so far.

but what can i add to my soil or water to help? preferably something cheap


and can anyone link me to the thread that has the pictures of leaves and the problems the have?

much thanks

Fox farm nutes. Mix 2 tbsp of big bloom along with 2 tso of grow big. Don't mix the nutes when concentrated. Fill half a gallon and add nutes. Half a gallon is good for 1-1.5 gallons of soil.