Tweaking Control IQ

I have read a bit about people tweaking their pump settings in control IQ for better control and tighter numbers by adjusting their weight, correction factor and basal rates. Can anyone tell me a bit more about that? My daughter is about to get control iq in the next few weeks.

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You need to be very careful with the settings. You first have to get things working right a month or 2. It takes a while… after I did all that I decreased my insulin sensitivity and slightly increased my basal across the board by .1
Running in sleep mode makes it tighter however it won’t make corrections when in sleep mode so you have to be on top of that.
I have settled into using sleep mode at night. I can keep myself in the high 90s even thought it wants to be 112, with sensitivity adjusted I run lower.

During the day I run in regular mode. However I still make corrections when needed.

But really you got to bet things running stable first. The limits are prey good for starting out anyway, her control will be real good by just doing it as it’s suggested.

I found I just wanted a little better control after I used it a while. I certainly would not make any big changes. You don’t want her going low .

Oh we’re definitely going to be very careful. At first it’s not so much the tightening up the control but to also loosen the control until we get accustomed to how it all works. To be honest we have a fear of lows and we need to work slowly into this. So I guess I was just wondering how you would adjust your settings up or down to make tighter or looser control. Obviously a higher basal setting and more aggressive correction factor will make tighter numbers but just wondered if anyone had any details or experience - in either scenario.

I am one of the outliers here. I have let the system just do its thing! I wanted easy and this system gives it to me.
My A1c is running the same as before but my time in range and my standard deviation is much better. And this is all with less work.
Now, I did make sure I had a pretty good basal profile, carb ratio and correction set up before I got the system started. But I set it up just like they asked. Correct weight, correct total daily units, insulin duration all set as directions asked for. I also use sleep mode for when I sleep and exercise when I do my extra long walks on my days off.
I find the system does exactly what I want and need. I am very happy with a time in range above 80% most times. I am very ok with a standard deviation around 40 or less. I don’t stress about things anymore. I don’t watch my CGM tracings anymore. I review every 2 weeks or so but really haven’t needed to make many changes.
I am pretty sensitive to insulin and carbs. So do I push the system sometimes, sure. I do find that once the system turns off insulin, I can let it ride without taking any carbs because I doesn’t take long with no insulin for things to correct. And most times because I don’t have super lows much anymore, a single glucose tablet can handle most lows.
So, like I said, I am one of the few that did absolutely nothing with the system. I just let it do its thing and I go on with my life. After 50 years of worrying about everything, it is super sweet to not have to think about it much anymore! My family worries less, my coworkers are less worried, everyone loves the system. It makes everyone very happy!
I hope you find this system user friendly and easy to use! And yes, there are plenty here who have helped the system work better for them. Each one of us is very much an experiment in the making. What works for me, might not work for you. Just take every misstep as a learning experience! Good luck!


Control-IQ uses your weight and TDD as part of the algorithm to compute the maximum amount of extra basal and/or correction insulin it can deliver.

I’m not very sensitive to insulin, so I use the maximum setting of 307lbs there, even though I really weigh around 120. Personally, I’m trying to eliminate that restriction on the system. If I was more sensitive to insulin, and fearful of it, I probably would leave that be and not tweak it.

It doesn’t really matter what you put in the TDD setting. That is only used for the first days on Control-IQ, before the pump has acquired enough data to computer your actual TDD. Once it has enough data, it uses your actual TDD to help determine the limit.

Since I run in sleep mode all the time, my set basal rates don’t matter much. The pump is going to change them, based upon correction factor. It’s simply another setting that makes insulin available if I need it. I usually run it marginally high, like maybe 10%. It’s not enough to crash my BG if I lose CGM, but it still makes a little extra insulin available to help keep me in the narrow target. Now, I’ve gotten really lazy about weighing/counting carbs. I usually just guesstimate. So, for two hours around my usual breakfast and dinner times (I only eat twice a day usually), I do run an exceptionally high basal. Nearly double what I actually need, because if I guess wrong, the pump can take the extra insulin needed from my basal and reduce/suspend whatever I don’t need of that basal rate. Since I’m awake and alert, I’m not worried about the “what if the cgm isn’t working while you’re running all that insulin?”. I still know and trust that I’ll catch and react to possible hypos. I’m knowingly taking on extra risk risk with this settings choice, but I’m comfortable with the risk and I find the reward for it excellent! I can’t advocate that others make the same choice, though. I know many wouldn’t be comfortable with such an intentionally high basal.

I also run a SLIGHTLY lower correction factor than my “tried and true” setting. As in, smaller number/more aggressive setting. Instead of 1:46, my sweet spot is 1:42 (9% less). The aggression works in both directions, so it helps curb any time spent above 120, but also works better to prevent lows. I find that I can’t go any lower with that setting, though, or my standard deviation goes higher, and I start getting big swings.


Thank you for your responses. I appreciate your thoughts. We will set it up as directed and see how it goes. One thing I think my daughter will have to change is that she doesn’t tend to pre-bolus much. From what I read if you don’t prebolus
and go too high you’ll end up with more iob than you need.

That has happened to me, but CIQ reduced basal, so the bolus/iob insulin essentially behaves like basal. It’s a new way of thinking.

A question: does the correction factor affect how much Control-IQ adjusts basal when you are in sleep mode?

That is, I understand that in sleep mode Control-IQ will not automatically give any correction boluses if you’re running high but that it will automatically increase your basal. Does the amount by which it changes the basal depend on the correction factor or does it just increase by a given percentage over your default basal based on its prediction of how high you’re going?

The basal adjustments are nearly entirely based on Correction Factor, but it uses the weight you program and your total daily dose (computed, expect for the first few days where it doesn’t yet have sufficient data, then it uses the programmed setting) to limit how much additional insulin the algorithm is allowed to deliver.

Percentages don’t play at all. Even if your basal rate is set to 0, you can still get basal increases.

You still get corrections in a way with sleep mode, it’s just a slooowwwwwww correction. It’s kinda like trying to lower your BG with an extended bolus. Much better to just stay on top of it and do manual corrections yourself, if necessary. But small corrections, it can handle like a champ.