If you're gonna buy the jugs, you really should get some sterile vials to store the excess in. You can preload a cycle in syringes, but you don't want to leave anything in the jug after opening. Another solution suggested by IP is to preload all of it into syringes (perhaps 5 or 10 cc), place them in a sealed ziploc & store in a dark container in you fridge. Personally, I think storing excess in vials is best and you can pick them up pretty cheap online---a couple of 30 cc vials and some syringes and you're good to go with the 70ml Sust.