can anyone plez help?

Ok i got some fert's from a friend and he it should be for flowering, veget.. and Ect. But the shity part is that he lost the bag or box that it cme in, so he said he THIKNS'(wich really aint good for me)that it should be 1 "heaping" spoon full per gallon. So can anyone tell me if this is right, and if 15-30-15 will even work for me. or should i look for something els, all i could find ot here so far is 10-10-10, and i didnt get it cause i got this 15-30-15 for a friend.

15-30-15 is good.there are far more advanced fert and stuff, but that is good for the average person

you only want to put 1/4 teaspoon per gallon.