So, hypothetically has anyone ever run the reservoir down past zero? Due to a comedy of errors yesterday, we did, and I'm trying to figure out exactly how much wiggle room there is and what happens when the pump registers zero units left in the reservoir. Here's what I can piece together: 10:30 a.m. Low Reservoir alarm (set to alarm at 20 units left) 4:30 p.m. Low Reservoir alarm (set to alarm again at 10 units left (or maybe that's a factory setting???)) Those are the only two things that show up in the alarm history. At 11:00 p.m., the CGM alarmed. High SG, and two arrows up on the CGM. At that point, I remember my dad telling me around 5:30 p.m. that Jack had gotten a Low Reservoir alarm earlier, but I wasn't too worried about it, as I assumed it was the first alarm. So I check the status screen to see how many units he had left. Zero at 7:00 p.m. Holy youknowwhat! So I give a massive correction and a temp basal increase. Because it actually wasn't that hard to bring him down, and he never really got above 250, he must not have actually been without insulin for very long. So my question is twofold: 1. Is there an alarm when the pump registers zero units left in the reservoir? It does not appear that there is, and if not, why the hell not?! 2. It appears that there is a "reserve" of insulin that is still there even after the pump shows zero units left. If he truly didn't get insulin from 7pm to 11pm, he would have been HI with ketones, and it would have taken him forever to come down. I'd guess that he probably was only without insulin for an hour or so. Does anyone know how big that "reserve" of insulin is? (I'd probably guess 5 units???) I'm just glad I remembered to check the reservoir. Otherwise, I think I would have been correcting and correcting and not knowing why it wasn't working. It could have been a real mess!