Requesting Any Tips for making smooth switch/transition from Medronic 670G to T-Slim X2 Pump and Dexcom G6 for 14 year old daughter?


My 14 year old daughter is getting ready to make a switch to the T-Slim X2 insulin pump and Dexcom CGM G6. She currently has a Medtronic 670g pump and uses the closed loop feature (Auto Mode). The problem with Medtronic has been the sensors (they don’t last very long and are very painful when inserting). Before we begin the process of switching, I would like to hear from others who use both systems. Any tips or recommendations would be greatly appreciated. Pump training will have to be done via Zoom with her endocrinologist’s office. Thanks so much for your input!!! Cheryl (mom of T1D teen)

I’ve been on Dexcom + Tandem t:Slim since 2017. Before that, I was on Dexcom (since 2015) + Medtronic 723. I just recently got the Control IQ update to my t:Slim, but the real game-changer was the Basal IQ update a year ago.

Medtronic’s Auto Mode and Tandem’s Control IQ are similar, but you will probably notice once you make the switch that the Tandem is a lot more user-friendly, the sensors don’t hurt (at least on me!), and the Dexcom is more accurate. Dexcom G6 is I think one of the only sensors FDA approved to make treatment decisions based on the readings.

I actually have a podcast on T1D and my 17-year-old co-host has the Medtronic 670G, so during most of the episodes we talk about both of our pumps, the pros and cons, and the different features. I’m happy to answer any specific questions you have about the Tandem system.

Hi Cheryl @cherylkilpatrick, it is good to see you return to the forum, and in my eyes, I think your daughter is making a very good choice of devices.

I did not change from the 670G system, but from an older MiniMed Medtronic, but as with all new devices, make certain that your daughter thoroughly reads the User Guides and comprehends the process. I changed more than one year ago to the Tandem t-Slim x2 pump to use with a DexCom G5 which is the most accurate continuous sensor and only began with the G6 in December. Using Control IQ now for two and 1/2 months - AWESOME!!!

Each transition was very simple and I didn’t need any training - the week my new pump was delivered, the trainer for Florida had to go the the Tandem facility to learn the new stuff coming out. What I did, was copy my old MiniMed patterns into appropriate “Tandem Profiles” and made a few tweaks. Basal rates are most important, so I very strongly suggest that your daughter validate her basal rates before beginning the CIQ.

Currently, with Control IQ, the only thing I must do is enter carbohydrate count and activate/deactivate the “Activity” feature when going for a bike-ride, etc. With CIQ, I’ve been able to achieve greater than 90% TIR [Time-in-range] and only a couple of “lows” when I over-worked or severely miscounted carbohydrates. After a couple of days, I silenced most alerts and now just have the alarms activated. At times I almost forget to even glance at my pump which is also my sole DexCom receiver.


Hi Cheryl,

I’ve been on both. I used the Medtronic 670g closed loop for about 6-8 months. I called it my newborn baby- constantly waking me up all night, needed to be calibrated so many times, calibration not accepted, etc. I was testing my BG about 10-15 times a day! So annoying. I switched to Tandem X2 and Dexcom G6 about 8 months ago. Best decision EVER. I am so much happier. I have not yet upgraded to Control IQ because, as Dennis said, it is important to have your Basal rates really dialed in and I want to do some basal testing. But… I am a Nurse Practitioner and have been working long hours with more stress so not the best time for me right now to get accurate basal testing! So… I’m still using Basal IQ which works well and is very sensitive. I think one thing your daughter will LOVE is not having to do finger sticks. Its truly amazing and in my opinion the Dexcom G6 is a million times better and more accurate than the Medtronic CGM. My medtronic CGM sensors often lasted 4 days then would fail. The vast majority of my Dexcom G6 sensors last the full 10 days. The other thing I think your 14 yo will love is how much smaller the X2 is than the 670g, more discreet, less invasive, easier to tuck into your pocket, etc. It really makes a difference. And the interface touch screen is easy to use. The only downside is it takes longer to load. In my opinion that is a VERY small price to pay. Also, it has a rechargeable battery which is good and bad… I bought a $20 portable charger on Amazon, which I personally find to be the easiest way to charge. Some people get in the habit of always plugging it in when they are in the shower. For me, I tend to wait until it alerts me that its at 25% battery then I attach it to my portable charger and can still move around. My guess is that she will be really happy with the change. The other GREAT thing… she can get her readings on her smart phone if she has one, so if she wants to check her #s she can pull out her phone and look verses the bulky 670g, which for a 14 yo is probably a big deal. And you can be added as a follower so you can also track her numbers, which I know a lot of parents LOVE that peace of mind.

Hope that helps.



Hi @cherylkilpatrick,

I used Medtronic for over 20 years, including 1.5 years on DIY Loop with Dexcom G6. No personal 670 experience, except for having T1D friends who hated it. I just switched to Tandem X2/Dexcom G 6 last week! My main tips are:

  • view and review all the appropriate training videos for the pump, pump features including CGM and Control IQ, using CGM, filling cartridges, and inserting infusion sets.
  • Review your daughter’s current insulin pump settings, for basal rates, carb ratios, correction factor, and duration of insulin action.
  • Assess - how are those settings working when your daughter is not in auto mode.
  • Expect to have to retest settings after you migrate to Tandem/Dexcom.

If you use Facebook, consider joining closed Tandem X2 user groups, especially the one referring to tighter control.

Tandem/Dexcom is the best commercial system available today IMO. I think she will benefit from it.

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I’ve been T1D since 1965 and have used a pump, the Tandem T-Slim, since 2013. Do the math and you’ll see I injected for a long time! I’ve used the G6 and Control IQ for 3 months now and love it. It is very user-friendly and I’m not very tech-savvy. My A1c has been below 7 and I love how easy my overall management has been. I have not had any insertion pain; in fact, the only pain I have experienced is with Medicare and my advantage insurance delivering my refills in a timely fashion. Good luck figuring out what works best for you.

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I am a T2D who made the switch from Tandem’s Basal IQ to their new closed loop Control IQ technology on the t:Slim X2. Abbreviations: Control IQ = CIQ, t:Slim X2 = X2. First, for as much as possible, use the online training from Tandem itself. Tandem’s training is professionally done and screen shots appear to be either well done zoomed in camera shots or computer grabs from the actual software. There are no fumbles with video chat and a tablet or phone.

Second, turn on and use the Dexcom Clarity and Share features. This will allow you to follow the BG tracing in near real time. Remember the Dex CGM is every 5 minutes. My family and clinic follow me and alert me to wild swings. As far as the sensors go, the Dexcom G6 sensors are GREAT! I have used G6 for more than a year and have only had two sensors that did not last the full 240 hours (10 days). I called Tandem on one failure and straight to Dexcom on the other. I had a replacement sensor delivered by FedEx overnight.

Mobile t:connect has not been released, YET. It is coming according to Tandem. Details pending.

The biggest hurdles will be 1) learning new vocabulary (you already know about how long insulin lasts in your teen’s body, the ratio/relationship of carbs to insulin, placing insertion sets, how to insert a CGM, etc) 2) learning mechanics of X2, 3) learning alarms on X2, etc. You are changing from a pickup truck to a fine sports car.

Remember to get a receiver for the CGM if there is any place your teen will go (must know when CGM sensor is changed) where she will not be able to take her phone. Some places where you might expect a push back and need to handle a NO PHONE ALLOWED are 1) ACT/SAT testing, 2) called to a court room, 3) certain Gov’t Offices, etc.

You and your teen have made a great choice switching. Learning new terminology is learning curve.

My daughter, age 7, has been using Tadem T-slim and Dexcom for about 2 years.
I love it! Especially now that it has Control IQ. I did Tandem training online. It is very easy to understand. Dexcom is great too!

Hi, there is a lot of good advice already posted on watching the Tandem videos etc. so I would like to just add one small suggestion. If you prowl through the Tandem website, you will find a worksheet that helps you to move setpoints from other pump manufacturers, to Tandem. The worksheet is helpful because Medtronic sorts setpoints in one manner (by Basal, by Carb ratio etc) while the Tandem T-Slim X2 sorts everything on clock times. You might like to complete this before your training and then it will be smoother to move all of your setpoints. Of course you could figure it out on your own but the worksheet facilitates it. Also, just to be safe you might like to make a “Final” printout of all of your Medtronic setpoints.


Very good point @RMcM, and by writing down ny own information before I moved from MiniMed pumps [three different models over a period of many years] to Tandem helped me to begin changing my “thinking” process. Tandem Profiles are more comprehensive than MiniMed/Medtronic Patterns.

Additionally, a very good Tandem pump simulator can be downloaded from the site; I had my Personal Profiles entered in this simulator for practice before my pump was delivered. A word of caution if you fully use the “simulator”; I had the simulator loaded on a tablet and had entered a short 4-hour “Auto-OFF” - my simulator awoke me during the night telling me I hadn’t touched my pump for a while.

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