Well, like they say "learn by doing". I learned alright. I had heard from others on different sites that you can retrieve insulin from an almost empty reservoir and redeposit back into the bottle. Don't do it. I done this at least twice so far and it backfired this weekend. I had really good blood sugars on Thursday. I had just changed my site the day before because I had ripped it out. I changed just the infusion site and hooked back up to the pump. The reservoir needed to be changed when I got home on Thanksgiving night and there was still some insulin left in it. I pulled it out with a syringe and redeposited it back into the bottle. Friday Morning at 2 am my blood sugar was 198 and remained like that all day and creeped up to 300 by 8 pm. I thought it might be the insulin so I threw out the two bottles I had on the table and filled my reservoir with fresh insulin. Voila, blood sugars have been within my target range at bedtime, early morning and within two hours after eating. So whatever you do don't attempt to reuse the insulin left in the reservoir, Throw It Out.