Planning my first cycle, few questions

[dce2956]

I'm 20, 5'8"-9", 170, ~14% BF, and planning my first cycle. Right now im thinking of 500mg Test Enan. and 300mg Deca a week, 2 inj. per week, 1 inj 250mg Test, 1 inj 250mg Test and 300mg Deca. Planning on doing the Test for 8 weeks and Deca for 6. The plan is essentially the Test/Deca cycle in Phreezer's sticky The deca i can get is in 200 mg per amp though, and I don't know if once i open the second amp of Deca to get the extra 100mg if i can leave the amp open and use the other 100mg next week? Maybe put some plastic wrap over it and keep it in the fridge? I'm currently in the saving and planning phase and I don't think i'll be able to start the cycle until november, so i have plenty of time to tweak the plan, and any advice would be appreciated.