you'll need it in the future so it wont be wasted. you can get a little packet that will be more than enough for a couple bucks. a weekly fert schedual is for heavy growth or traditional bonsai soil with no organics in it. with no organics the fert is the only food the tree has to survive
ok so guess I need to go to the store and see if I can find aslow release thats more even. I was thinking that this one wasn't going to work so glad I double checked.
nitrogen promotes leaf growth,potasium promotes flowers( not a concern with maples) potash or K is for root growth.basicaly if you want it to grow alot what you have will work . for more of a maintainace id go 7 to 10 in the N and K stats