Crystal, here’s a discussion on splitting Lantus:
https://forum.tudiabetes.org/topics/t1s-on-mdi-whats-your-lantus
Since that discussion I’ve reverted to a single shot of Lantus, because even a 2-unit dose at night tanked me by morning. Then I moved the morning dose around until settling on what seems to be working (9:00-9:30), which prevents me from tanking early to mid-morning but also from elevating in the late afternoon.
I regret I don’t know all there is to know about experimenting with basal dosing (lots of people on this board who are very well-studied). My decidedly not-as-educated opinion is that 20 units of Lantus seems like a lot with a 1:15 carb ratio; I do 17 units of Lantus, and have an I:C of 1:6.
I wonder, too, if your I:C is correct, particulary with respect to your dinner meal. Is it possible that both your Lantus dose AND your dinner bolus could use adjustment? Either way, always better to tweak one or the other rather than both so that you’ll have a control factor (e.g., which adjustment is doing what?). And, remember to observe one adjustment over a period or four or five days before making another…
Good luck, and post back with results!