The vial should be vacuum sealed so just be careful when you initially insert the syringe into the vial as the water will get sucked in pretty quick. Personally I just use BW to dilute my GH. Just to keep things simple I just go by IU's and not by the mg contents (it should tell you how many IU's it is 5.8mgs should be 17.4ius so if you dilute with 1.7cc's of BW it should get your every 10 units on a slin pin should be 1iu of GH roughly.