# Missing Insulin - Possibly leak I can't see? **URL:** \ **Category:** Pump\ **Created:** [December 6, 2019, 10:17pm UTC](https://forum.fudiabetes.org/t/missing-insulin-possibly-leak-i-cant-see/8830 "2019-12-06T22:17:59Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [December 6, 2019, 10:37pm UTC](https://forum.fudiabetes.org/t/missing-insulin-possibly-leak-i-cant-see/8830/2 "2019-12-06T22:37:07Z")
The 50 unit mark is based on plunger position, not actual units left in the pod. It is an estimate. So there might be a fault with the signal from the pod, basing it on a faulty read on the plunger position. Where it shows the units left in the pod, it will never be as accurate as your own math. If you know what you have put into it, you can subtract about 7.5 units of deadspace and priming, and that is what you actually have in there. This thread is extremely detailed, but not very easy to understand. It was kinda tough to explain this all. The simple guess I have is that there is an issue with that pod’s detection of plunger position. I would not base anything on that 50 unit number they give. > [@The OmniPod's "reserve tank"](https://forum.fudiabetes.org/t/the-omnipods-reserve-tank/1957): > > I have been tracking this down for a while. Finally got a somewhat official answer, which matches the tests and numbers I came up with on it. If you are a OmniPod user, the conclusion may possibly be of use to you at some point. The OmniPod PDM shows units remaining. But is it never exactly correct. I always noticed a bit more insulin in the pod than what is actually displayed on the PDM. But the “how much” was somewhat of a mystery. So I started loading my pods with very specific amounts wit… --- _[View the full topic](https://forum.fudiabetes.org/t/missing-insulin-possibly-leak-i-cant-see/8830)._