It all depends on what type/brand fertilizer it is.
There are dozens of brands of fertilizer, and some are more highly concentrated than others. Follow package label info for amt. If it's a chem. fertilizer, consider using 2/3 recommended dosage cause that stuffs harsh.
I recommend using organic nutrients.
I also recommend that you feed a low dose of fertilizer every time you water, instead of a single dose per week. For instance if it says to use "X" amt. per week and you water twice a week, use 1/2 the amt. each time.