hey brother, you want to use bacteriostatic water, not sterile water that often comes with the HCG. That is designed for one time use. You want to use an insulin syringe to measure this stuff because the amount of fluid will be so small. I could use more info to better help you but I will assume you are using this on cycle. In this case, through your cycle, I would time it up so that you can inject IM around 250iu, every 3 days right up to a few days before PCT starts. As for mixing, if your vial is large enough to mix 5cc water into it , each .5cc water will be 1000iu. So each .25cc will be 500iu. Each .12cc will be 250iu. So you would want to inject .12cc (ml) every 3 days.