Control IQ with restarted sensors

We still haven’t got control IQ yet. But I was wondering what people’s experince with it is when they are using a restarted G6 sensor. I find that when i restart a sensor, the sensor is a bit wonky for the first day. Subsequently it becomes better but still somewhat a bit off and at times there are no dots recorded particularly towards the end of its life.

I worry that this will mean that control IQ will be off too (so may deliver too much or too little of insulin based on the readings). Do you turn off control IQ when they are using a restarted sensor?

How far off are we talking? No system can be stronger than it’s weakest link, so the accuracy of your sensor is definitely a limiting factor. That said, the sensors are allowed to be off by 20%, even if most of us expect and get much better of them, so the system is designed with at least that much variation in mind.

Control-IQ doesn’t work without sensor data. It will default back to your programmed profile. Basically just becomes a "dumb"pump that is as safe as you or your medical team programmed it to be.

Reliable sensor data is important for the best results, but there are enough safeties and padding built into the system that it’s not critical to your health. Example, it can only deliver 60% of an automatic correction bolus when you’re too high (something I criticize, so thank you for illustrating one reason for the precaution). It’s enough to get you down out of the clouds, but not enough to bring you back to the target BG, let alone drive you hypo. So there’s a LOT of wiggle room before it’s problematic. Of course, if you’re a lot higher than your sensor says, you run the risk of staying in ketogenic territory for too long if you’re but intervening.

Also, low prevention can’t really work if the pump doesn’t know you’re low, or heading there. No different than with Basal-Iq.

Are you calibrating after the restart warmup? I’m wondering if there’s a way to smooth out that 11th day trouble. My readings come in ridiculously high after a restart, but line up perfectly once it’s calibrated down, hopefully in just 2 partial steps. Some of the restart advice recommends not calibrating at all, though, and it will settle into place on its own within a day. If you want to go that route, you could just turn Control-IQ off for that day.

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I have restarted sensors because I’m not home and need to have data, also to just see how it goes. I don’t get as stable readings as I like and so I generally don’t restart. My insurances sends me 3 sensors a month so I don’t have a great need.

A lot of people calibrate them esp after restart.

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I have bad Dexcom results on the first day and often turn off Control IQ until the sensor is reliable. I used to restart G5 sensors because they were perfect after restarts and I avoided 1st day issues. With G6 the restarts require calibration and are just a new adventure. Since I have an ample supply of G6 sensors, I have no motivation to restart them. Interestingly my new sensors read low the first day. My restarts read high the first day. But I sm lucky that after the first day my sensors do great and they always last the full ten days.

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About +/- 1 mmol (18mg). My sensor readings on the restarted lifespan is always not as reliable as a new sensor on its first 10 days. I pay for this out of my own pocket so I stretch it to the max.

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Yeah I always restart without code, I find it easier (and faster) to align the readings with the meter this way.

For me I’m not sure whether presoaking actually makes a difference. A lot of the times my first day is still a bit off. I try to leave it alone and not calibrate but the temptation is always there :smiley:

It’s funny how different we all are. I’ve tried the no code way twice, and both times were awful for me. I had more rejected calibrations and wasted test strips than by just stepping down a coded restart. I was so mad!

I pay out of pocket, too, hence why I’m all about the restarts and sucking every last day I can out of them.

Are you careful about when you feed it the required calibrations? As in, before meals/boluses, when you’re flat-lined. If so, I guess there’s not much that can be done about the wonkiness. I don’t think 1mmol is enough to stress over, though. At least not just for a day here and there. Control-IQ is built with a 6.1 mmol target, at least for now. It’ll probably be more customizable by the time you get it. Would you stress about actually floating around 5.1-7.1 mmol, instead?

Yes I’m consciously looking at the right time to calibrate and making sure my BG isn’t super high or low and arrows are not trending either way. I always get told off by customer care here when I call up about a wonky sensor ( not a restarted one, one that’s inaccurate during first 10 days). They keep lecturing me not to calibrate so I stop telling them I calibrate…. only to be told I should calibrate once and see before they are willing to replace the sensor! So you can’t win.

Not so much in this range but sometime when it’s lasted 10+ days especially when it’s about to die the readings are way off but then after a while goes back into some accuracy. It’s those super out readings I’m worried about. So I may be 6 and it tells me I’m 8.5. Or I’m 3.1 and it tells me that I’m 5.6. I do find it eventually lines back up so not quite ready to throw that sensor away just yet but probably need to when control iq comes.

A little bit off is annoying, but okay. Those big differences aren’t. If you don’t trust your sensor because it’s behaving badly, you should definitely switch Control-IQ off. It rashes just a moment, there’s actually an on/off switch. It’s easy to do. The only downside to switching it off is that you have no low prevention, either… But that’s not useful to you anyway with a bad sensor.

Control-IQ already has new features, theoretically. We just haven’t seen them yet in the US because they’re stuck behind the FDA wall. I would assume that the version of Control-IQ that goes through Aussie approval will be whatever is most recent, so who knows how it’ll work then.


A bit off the topic here but I wonder if one of the new features will be an opportunity to put in grams of fat and protein as well as carbs? Then it could work toward a customized insulin bolus profile.

I wouldn’t hold my breath for this :smiley: . We had control iq approved around oct/nov last year by FDA and still it’s not available here! We will probably get it when it becomes an obsoleted version for you. Snail pace at the moment.

Oh no! I just thought Tandem hadn’t filed the approval there yet, because it’s expensive and manufacturers try to hit their biggest markets (US/EU/UK) first.

I wonder what the holdup is then? There’s nothing to distribute, the software is written, and the approval is in place. I don’t understand what’s missing. They’ve just got to let you plug your pump in and download it.

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Exactly my thoughts!! I think it’s just bureaucracy getting in the way. Imagine if there was a hardware refresh, would take even longer.

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Canberra is slow. Waiting all of the Commonwealth Nations to act together.

At least Canada has CIQ but no tConnect.

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Holy cow! That would be so sweet!!! I had my pizza delivery perfect before Control IQ. 25/75 with a 5 hour length. It took me a long time to get it right but I loved very experiment! Because I love pizza! But now with Control IQ, I am back to fighting with it. It only allows a 2 hour extended bolus. The thinking being the system will automatically increase basal as needed. But man those last 3 hours are when all that cheese is hitting my system and the system can’t keep up. Oh well, more experimenting!


I regularly turn off Control IQ when I want to do things like stop long insulin suspensions or use a Temp Basal or a long extended bolus. Fortunately it is very easy to turn Control IQ on and off. Since I use Sleep Mode 24/7, I also have to remember to turn that back on. But that is my current compromise with Control IQ. I am not willing to totally abandon Control IQ because I really enjoy a D-life with few or no lows.


Wow my sugar would hit the roof on 25/75 extended bolus for pizza. I never could reduce is below 60/40 and then a massive temp basal afterwards.

What’s special about sleep mode, a lot of people have commented they use this permenantly.

Sleep mode targets a range of 112.5-120 while regular mode targets 112.5 -160. Sleep mode does not have automatic boluses but does manipulate basal to target that tighter range.


Was that a typo? Because it’s worse than that at 112.5-160 (6.25-8.9 mmol), as supported by your picture. Or do you know something else, and that it does actually start mitigating highs before 160? My understanding is that it leaves you to your own devices unless it predicts you’ll cross the 160 line.

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