Moving from Just Pump to Pump with Hybrid Closed Loop System

My Medtronic Paradigm is out of warranty, and I’m strongly considering moving to a hybrid closed-loop system for my new pump AND switching from Medtronic to Tandem. I’m interested in hearing opinions and experiences on how challenging it may be to make two big switches like that at the same time. Is that too much change? Thanks in advance for any info you can provide!

hi @sbeiers Susan. Do you use a CGM now?

T’slim, in manual mode, is exactly the same as your old pump (so there’s no change). With a CGM that works for you, Control IQ will increase or decrease insulin to help you stay in range longer.

Some people find CGM to be great, some don’t. There is a portion of the population for which the CGM doesn’t work. In some people, the CGM causes pain and irritation, and some find the CGM completely and unacceptably inaccurate. As with ALL gizmos, it adds a new set of failure scenarios and requires you to be comfortable dealing with CGM alarms warnings, comm failures, and have awareness regarding calibrations.

All feedback pumps including Medtronic and Tandem, require you to “not lie” to your pump and to deal with exercise and exact carb counts (not guesses), This is a very important concept because the pump is learning your carb input and your BGL feedback; “Lies” (ok lets say exaggerations) in an attempt to adjust for a bad carb guess begins a “fight” between you, your BGL, and where your pump thinks you should be based solely on your input and BGL output. Finally, you can fully expect a feedback pump to not be as aggressive as you might be.

If you had super tight control with your pump and used temporary basal rates and multiple carb ratios and sensitivity… you might find feedback pumps less appealing. If you go by 1 or 2 settings and deal with highs by corrections and lows by adding carbs… you might really like a feedback pump.

Feel free to do a search on the site for many conversations regarding G6 and T’Slim, or click these search links


I have been running Loop, a DIY closed loop program for over a year. It uses the Dexcom G6 CGM and an older hackable Medtronic pump. I am in the process of switching to the Tandem t:slim X2 with Control IQ software, which also uses the Dexcom G6. I don’t make this decision likely, because Loop is a life-changer. When you integrate a high quality CGM with an insulin pump, it is a much better world. I totally recommend the Tandem + G6 combo. It is absolutely the best commercial system available today. There will be a learning curve and a time of adjusting your settings so they work accurately with pump software. If you aren’t doing so already, I suggest you monitor a Tandem X2 users and Tandem with CIQ users groups on Facebook.

Hi Susan @sbeiers, I too used MiniMed Paradigm pumps until my last one was one year out of manufacturer’s warranty and 13+ months ago got a Tandem t-slim x2 - the pump by itself, without integration with a glucose monitor, is far superior to the Paradigm, and now that I changed from Dexcom G5 to G6 monitors I’ve found the Basal IQ and for the past month, the Control IQ to be really awesome.

But before you begin using these “closed-loop” systems, it is my suggestion that the pump and it’s personal profiles be in good shape to obtain maximum benefit. That means, have your basal rates, your insulin to carbohydrate ratios, and your sensitivity factors properly calculated and entered in your profiles.

Since I began Control IQ, all I need to enter in my pump is a fairly accurate carb count for EVERYTHING that goes down my gullet and NOT ever add phantom carbohydrates. In a discussion yesterday with the endocrinologist who wrote the prescription, I explained to her my findings and she in-turn exclaimed at the 94% time-in-range [TIR] the system helped achieve. Don’t try to “out-think” the algorithm, let it learn your body and then do its thing.

In addition to increasing, decreasing, and suspending basal insulin, the system also calculates and delivers bolus insulin if BGL reaches or exceeds 180 mg/dl. My mind gets boggled when I look at the pump history and see the many, many changes the device makes on its own in both basal and bolus insulin. Of course, the entire User Guide must be read and understood before embarking on either Basal IQ or Control IQ.


The algorithm doesn’t learn anything from you. There’s no artificial intelligence built into the pump. This same line of BS was stated when the 670 came out and was quickly debunked. If your BG goes above 180 it gives a mitigated weakass bolus. If you fall below 110, it chokes the basal rate down to nothing. If your BG is between 110-179, the pump does absolutely nothing. There’s nothing magical happening.

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@Jason1, it’s a common misunderstanding, not BS :slightly_smiling_face:.


I have been given the same information regarding my Tandam pump and I am now on the 4th replacement pump in 2 years.
I also dislike the representation from Dexcom stating “ no more finger pokes” that’s such bs.
I’m pretty sure this site is monitored by the representatives from the company’s employees. Just saying…

Hi @Beegee10 and welcome to TypeOneNation This site is for people with T1 to help others withT1 or caring for someone with T1. One of our members may in fact work for Tandem or Dexcom, but all efforts are made to just share our own truths. For example, neither DEX nor Medtronic CGM work perfect (or even satisfactory) for me, and so that’s why I don’t use either one. I hope you enjoy the forum.

Thanks for the reply!
May I ask what you do use? Or do you just test?

I have tried the older Dexcom and 3 generations of the Medtronic “guardian” type sensors. At this very moment I am considering Tslim + Dex G6, but I have not committed. Maybe I am waiting on G7 =) I have Onetouch, Livongo, and a Bayer Linc meters, Right now I use the Livongo with the Bayer as a backup, because my company pays for all the test strips… free and unlimited.

My daughter is a T1D. She is in Middle School. She has had the T-Slim since she was in 2nd grade and we love it! She also did the G5, but didn’t like how often she still had to prick her finger and correct the CGM. The G6 has been a life changer! With only the periodic finger prick, and the accuracy is amazing! Then add the Control IQ, and wow!!! Total game changer! Her BG is in range a lot more often, and she hasn’t had as many lows either. I would definitely recommend it!!!

Good luck!!!

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