I just don’t understand how they are murky. It’s not like, on a manual pump, your basal is ever magically covering food that you’re eating without you knowing it, or you’re bolusing unknowingly every day to cover some of your basal… If you’re testing basal rates properly by fasting through meals, neither of those are necessary. If anything, those types of scenarios would be more common on MDI where basal can’t be fine-tuned to variations that the body might need. On Lantus I had to wake up every morning at 3:00 AM to give myself 2-3 units of Humalog so I wouldn’t wake up at 10-18 mmol/L from the dawn phenomenon. Now that I’m taking metformin I doubt that will be as much of a problem, but I’ll be very curiosu to see what happens overnight tonight!
I suspect you’re about to see how they’ve been murky for years, maybe I’m wrong.
I feel like you just think they’re murky because you’ve never used a pump. 
I really have no idea how you could mix up the two on a pump, with the exception of the AP systems.
This is truly going to be a terrific thread!!!
Update: treated low with 16 grams of carbs, knowing it was too much but not knowing if I’d keep dropping from insulin on board. My CGM has gone to ??? during warmup, so I might be stuck testing every 30 minutes for the rest of tonight. Have now rebounded to 8.8 mmol/L and appear to be shooting up pretty rapidly. I’ll correct with one unit. Having dinner shortly that will probably only amount to about five grams of carbs (chicken and celery and dip).
Or maybe I should just leave 8.8 alone rather than get into a potential roller coaster…
Boy good thing you didn’t leave your pump on 50% 
I’ll test in another 30 minutes or so and see where I am.
Back down to 7.3 mmol/L. Not a fast drop (I don’t think), but I haven’t taken any Fiasp yet but have eaten dinner. So I’m thinking Tresiba dose is too high. Thankfully, my CGM is warming up, so I think that should be back up and running soon!
[Edit: now at 8.5 mmol/L. I think my meter may be having very rare accuracy issues!]
Hmmmm. Maybe I should have done the 50% basal with my pump…
And, well, the site won’t let me upload images without resizing, which I’m too lazy to do. Suffice it to say my BG has been steadily rising for the past three hours. It started rising after eating dinner (and correcting) and just never came down. It’s now 16.4 mmol/L with an up arrow. I’ve just eaten a few carbs and done another correction, so hopefully my BG will start on a downward trend soon.
Okay, now at 21 mmol/L and still rising. It’s clear that I don’t have enough insulin in my system. I’m doing a 5u correction, which is a couple units less than my ICR would indicate to account for any insulin on board from earlier corrections.
These are the frustrations I cautioned you to expect. A couple hours ago you believed you’d taken too much. Give the basal dust time to settle while making corrections as necessary
Yeah, I just hope I don’t run quite this high (nearly 400 mg/dl) for the next three days… lol.
I don’t think you will, and if you do it will become clear that you need more, but thus far this just means correct as necessary like we expected
What’s your starting tresiba 1x daily dose?
I took 36 units. My pump basal totalled 36.4 units.
My wild ass hunch is that this is a good place to start but an amount that will actually end up being titrated downward instead of upward… I could well be wrong… but it wil take much more time to see for sure
Well, this is my “high” basal amount, so I’d expect it to drop significantly in a week or two anyway, since a week or so ago it rose by about 14 units in two days, so it will drop by a similar amount at an even faster speed, like over 24 hours… That’ll be an interesting process…
Well, try not to judge to much in advance how this molecular structure will behave in your body based on how a different one did… it could well prove to be completely different
Overnight report:
According to my Dexcom, my 5u correction at around 11:00 brought me down from 21 mmol/L to around 12 mmol/L by 2:00, where I then levelled out and stayed flat all night. This would fit with the three hour DIA I had set in my pump for Fiasp. However, when I tested this morning (woke up early because I was dying of thirst), my meter said I was 15 mmol/L while my Dexcom said 11.5 mmol/L, which is just over 20% off. This is the first 12 hours of a new (old) sensor, so I’m not sure how well the Dexcom can be trusted in its rendering of my overnight BG especially considering it was giving me ??? during warmup last night, which is usually the sign of a sensor that may have issues. And either “going crazy” or “flattening out” are the two behaviours that bad sensors are known to do. I’ll hold off on callibrating it until it requests one. In either case, obviously my correction didn’t bring me to anywhere near normal. No ketones, though.
I’ll eat a pretty much no-carb breakfast (eggs and bacon) and won’t take insulin for the food, but will correct my BG again.
@Sam (and others who use Tresiba), since none of my corrections have brought me down anywhere near normal (according to my meter, 15 mmol/L is the lowest I have been since I began to rise about three hours after disconnecting from my pump), if I continue to run this high all day, would you say it’s fair to up the Tresiba dose by a couple units tonight? Or will Tresiba really kick in to such a great extend that it’ll bring such high levels down into range without a change?