Tandem TSlim X2

How long does it take to get better and faster at installing cartridge, loading cartridge, putting in new infusion set etc. It takes me between 1 and 2 hours!! Any advice?

Did you get trained by a Tandem rep on how to fill the cartridge? If not, you need to be trained, there are videos on YouTube that demonstrate how to complete process as well. It should not take you more than 10 minutes to unpack all the supplies you’ll need, remove the air from the cartridge, fill the cartridge, prime tubing, insert infusion set, resume insulin delivery.

To answer your question, you should be able to complete the whole process very quickly after a week or so. It took me 10 minutes the first few times, after a couple weeks I’ve gotten it down to 5 minutes.

Thank you Jason. I have been trained by two nurses and have watched the videos multiple times. My biggest problem is the repeated removing the air from the syringe and from the cartridge. Tapping my finger on the syringe does not remove the air bubbles. Also there doesn’t seem to be a video about that process. Once I get the air removal down I think I will be able to proceed much faster. I appreciate your support as I am discouraged about the length of time involved.


@MollyB Hi Molly and Welcome to the TypeOneNation forum!

I agree with you that the Tandem cartridge is a nuisance - at least when compared with the MiniMed/Medtronic reservoirs I had used with my three previous pumps.
In January I began using the Tandem t-Slim x2 for reasons that make it, overall, the far superior pump so I reluctantly decided to put up with the cartridge hassle. In the beginning, I’m guessing that it took me about 10 minutes to get the cartridge properly purged and filled, but now the entire infusion-set/cartridge change takes me less than ten minutes. I keep an entire set-change supply including insulin in a plastic box on the kitchen counter at all times so everything is handy; just grab the box, check my calendar log for rotation-site, and set to work and finish quickly.

As far as air-bubbles, two things: do NOT keep your active insulin vial refrigerated and, with the initial push of air into the vial, have the vial sitting upright. Nurses especially are trained to hold a vial up-side-down and push air up through the solution - that is a NO-NO with insulin that I learned many years ago. Insulin, especially the analog types, easily retain air bubbles.


Thanks Dennis,

I appreciate your help. It takes me a LOT longer than 10 minutes but I am encouraged that I may get there eventually.

I have a very difficult time getting the cover off of the infusion set and bent two needles while trying to get the lid off. I have also inadvertently torn the needle out of the middle again in an effort of trying to get the cover off and/or unwind the cord. I am beyond frustrated but do not want to give up.

Don’t tap the syringe with your fingers to get the air bubbles to move to the top of the syringe. Instead, whack the side of the syringe with a pen a few times. Any pen works, I’ve found the fatter the pen, the better(Mont Blanc is my preference). This gets all the bubbles to the top so you can push them back into the insulin vial and draw insulin back into the syringe without any air.

Be sure to remove the air out of the cartridge before you draw any insulin into the syringe. The first thing I do, is insert the syringe into the cartridge and pull the plunger back as far as it will go. I then remove the needle from them cartridge and push all the air out with the plunger. I will do this five or six times before I fill the syringe with 200 units of insulin. Once you’ve filled the syringe with 200 units, insert the needle back into the cartridge and pull on the plunger a bunch of times. I do this very quickly and get all the remaining air out of the cartridge.

I’ve done this process countless times over the years and have never had a single air bubble in my tubing or a single occlusion.

If you’ve been trained by 2 nurses and still have major issues with filling the cartridge, you were not trained properly. The cartridge fill is somewhat tedious compared to other pumps but not difficult. You desperately need someone who has a lot of experience with the Tandem pump to show you how to do this process correctly. If I were you, I’d call Tandem to see if a representative in your area can meet with you and demonstrate in detail how to fill the cartridge correctly.

In addition to the other very useful tips already given:

I was trained to full the syringe with insulin, remove bubbles, then pull the air from the cartridge and remove bubbles again before pushing the insulin into the cartridge. Makes no sense! Now I pull air from the cartridge first, then get the insulin and remove air bubbles once. Much faster and easier.

Dexterity: I sometimes want to twist off the syringe needle cover or pinch the wrong half of the TruSteel clip. If parts of the process are just challenging to your fingers/brain, try taking some used pieces and practice the motion over and over. This helped me a lot.

Finally, I know I’m going to struggle with a cartridge fill if I’m too tired, BG is high, or I’m in a hurry. I try to avoid those times when I can.

Hope this helps, Mollie! You’re not alone on this journey.

1 Like

Thanks Lisa! Those are the two most challenging parts and I will try practicing with a used set as you suggested. Do you have advice on what to do with the long tubing. I get it caught on door knobs and once I pulled the whole set right out of my body!

Thanks again Lisa!


Molly, I am so glad those suggestions are helpful! This forum has been such a great support to me. I tuck my tubing into the waistband of my pants, usually, or a nearby pocket. Sometimes I’ll just pull a shirt over it, but as you mentioned it’s easy to catch on things. Best to keep it stowed. :slightly_smiling_face:

If you surf around, you’ll find a number of pump pockets and accessories on Amazon, Etsy, etc., and helpful YouTube posts on wearing a pump in different situations–exercise, prom dress, etc. Many creative ideas!

I am finding it so difficult to fill the tandem reservoir without also including a ton of air bubbles…or having some sort of difficulty using the tiny tandem needle/syringe combo. seems the needle isn’t securely enough on there even when it seems I have twisted it on firmly. I was trained by a nurse who warned me not to “over-twist” it on, and I don’t think I am, but it doesn’t seem to work as well as the already-assembled syringes I worked with pre-pump. I am just waiting for an occlusion alarm, even though I pretty much tripled the amount of insulin needed to fill the tubing, waiting until I didn’t see a succession of air bubbles. I keep reading about how this gets easier, takes less than 10 minutes. I have filled 3 times now and the whole process is closer to 30 minutes than 10. Is the trick really to just repeatedly push and pull the insulin in and out of the syringe? Anyone else have trouble getting the needle to properly fit on the syringe? Thanks!

Hi Elizabeth @elizabethm, I hear your frustration with bubbles in the Tandem CARTRIDGE fill process.

It pays dividends to avoid insulin bubbles right from the start when working with insulin - nurses, most of them, usually begin by pushing air into an inverted insulin vial - which is wrong. From my first attempt with insulin injections in the 1950’s, I’ve pushed the air into the vial while the vial was sitting on the table - both Medtronic and Tandem require this procedure. My next step is to invert the vial & syringe together and let the syringe fill naturally without yanking down on the plunger.

Next, insert the tiny needle in the white Cartridge hole [it doesn’t need to go in its full length], and pull up on the plunger and hold it that way for a minute, tap on the cartridge if you wish, until no more bubbles are seen rising. Then, with the needle pointing up, tap a couple of times on the syringe until you see that all air [bubbles] have risen to the needle hub, then expel all air from syringe and needle. To assure yourself that ALL air has been expelled, slowly invert the syringe while watching closely for bubbles. Finally, with the cartridge down, insert the needle in the white hole and gently push all insulin into the cartridge. At this point [hopefully] your cartridge will only contain insulin.

Screw the Needle firmly onto the syringe - it can’t be over-tightened. These syringes, which require needles to be firmly screwed on, are supplied by Tandem because they are many times less likely to allow air-intrusion than the preassembled friction type syringe and needle.

I hope that soon, you will become more comfortable with this fill-procedure.

1 Like

Thanks, Dennis.
I am trying not to get too frustrated. It has only been a couple of weeks–not even! I am wondering if I should just do as others do and fill the whole cartridge, or at least a week’s worth of insulin, and then just change the infusion site every few days, and just toss the new tubing and re-use the old. Alternatively, I could fill two cartridges at once and store one for a few days in the box, as you have suggested before. Doing this every 2-3 days is difficult, though I keep thinking all the practice will have to pay off at some point. Haha. Thanks again for your constant input and support here.

1 Like

All good recommendations here for purging and not getting air bubbles into your cartridge. One additional item that I noticed in your post, are you changing the cartridge with every new infusion set? I generally don’t do this, I fill the cartridge and it will last me 2-3 infusion sets. This greatly cuts down on the number of cartridge changes. For me, this works. Sometimes I will use the old tubing, sometimes I will use the new tubing, it depends on if I see anything strange with it or not.

Thanks, Joseph.
I have been changing the cartridge each time, trying to get the amount just right–and then kicking myself when I run out of insulin after 2 days. Next time (tonight or early tomorrow morning!) I will fill the cartridge with an estimated week’s worth. I only use about 25 units a day, but have been wasting a day’s worth trying to get air bubbles out. One question I’ve had about doing the full cartridge: When you change your infusion set, can you fill the cannula only (not the tubing) by going through the menu to “Load”? Or do you need to manually put in the cannula about, thereby screwing up the algorithm?

You can fill only a couple of units of insulin in the tubing and still fill the cannula with whatever you have your setting at. There are two options for filling, one says new, and that goes through the whole process and you have to fill a minimum of 10 units, the other is fill, and it lets you just fill until you hit stop. I use the fill whenever I change out my infusion set, then still fill the canula after inserting. One item I have noticed over time is that when my cartridge is low (below 10 units left) it’s not as accurate and I need to change before then. I usually fill my cartridges to the max and only change them out when they get low. I figure it’s less fills and less wasted insulin. I average about 30 units/day

1 Like

That’s very helpful. I see what you mean now about the two fill choices. I’ll need to use Load > Fill Tubing > Fill Cannula , but NOT “Change Cartridge” option, so as to avoid filling to a minimum of 10. I ran into that problem once when I tried to use the end of a cartridge that had 15 units remaining in it and which I didn’t want to toss. I’ve been told that after one week the insulin can start to deteriorate in the plastic cartridge, and I’ve experienced less effectiveness when I have approached 10 days with my old Medtronic pump. Maybe the last-10-units phenomenon you describe is due to time in the cartridge?
Really appreciate your advice. Thanks so much.

When I fill the syringe I hold it needle up to get the air bubbles at the top. I tap a few times - gently so as to try to form one big bubble without generating more. After that I press the plunger until I just see a little insulin shoot out - with the bubbles at the top, seeing that insulin coming out should mean I got rid of them. When I was first trained (on what was then Minimed - now Medtronic) I was taught I might see some tiny little champagne bubbles (that’s the technical term they used) but they were such a small fraction of a unit they wouldn’t hurt.

@MollyB, As far as air bubbles, practice is the big thing. I was trained by several nurses over time and shoot air into insulin with no troubles. I agree with whacking the syringe to get stubborn air bubbles to the needle end of the syringe. I keep a tongue blade in my pump packs for several reasons. Syringe whacking is one of them. The only caution I have is not to fracture the syringe. It can happen.

As far as keeping a cannula assembly in I am attaching a photo of how I tape things in place. I use AutoSoft XC sets & IV 3000 dressing.

Hope this helps with keeping the sets in place.

Hi again. I just remembered a tip: be sure you screw the needle onto the syringe firmly. No need to force it but make sure it comes to a full stop when you twist (I hope that makes sense) - that will help prevent extra air from getting in. Something my trainer taught me back in the day.

1 Like