The Ceiling and Floor Lines on the CGM

So my wife and I were having a conversation about what we should put those lines too. My thought is 150 for the ceiling and 80 for the floor. My rationale is that the gray area in between is where I want him to be as much as possible. When he goes above 150 (single or double arrows up), I know it’s time to start thinking about a micro-bolus to avoid him getting to 200.

I know it’s nothing more than a visual representation and “reminder” either way, but I am wondering what lines NORMAL people use…not you flat liners…I know you have yours set at 70 floor, and 80 ceiling…or something totally unrealistic like that. :stuck_out_tongue: But, everyone else…what is your rationale for setting your ceiling and floor lines on the CGM?

As to why I have 80 as the floor, I guess, using the rationale I am using above, We should probably set the floor to 100.

So I just wanted to get your input as to what those lines mean to you and what rationale you use when setting those lines. Again, my rationale really is that “that gray area is where I want to see him to live as much as possible”…the lower I set that ceiling, the better his A1C.

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Mine are set at 60-130 or 140 but I suspect they would be different if I was monitoring a young child instead of self…

In general you don’t want the cgm alarms going off excessively unless they really need to prompt an action most of the time… or you can end up growing numb to them

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My floor is set to 70. I don’t have a ceiling set because I’m constantly looking at it and because I don’t want the constant alarms.

I think your rationale is good though for a child.


I have my high at 140 and low was at 80 because I really wanted to head off the hypos. Having used xDrip+ for a while now I’m comfortable with the low set at 70, because I get a notification on my watch of the predicted time until low. Usually it’s a 45-60 minute time frame so there’s plenty of time to react.

Now, if they would only implement predicted highs I would be set.

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I would love it if you’d explain in a post what xdrip is and how it works, I really have no idea but it sounds interesting. I am not very tech savy.

I’m working on it. It’s also a setup guide. Lots and lots of marked up screenshots, so the going is a bit slow. May need to be a multi article thing.

Not trying to intrude, but if you have a bunch of markups to do, Powerpoint does a brilliant job of this activity. I usually mark up a few CGM traces for our physician appointments.

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We started out with 90 and 160, then moved to 80 and 200 to avoid the crazy number of alarms we were getting. On many nights with the growth hormones we have removed the high alarm when we aren’t willing to wake up and deal with it. Our goal now is to adjust our settings (sometimes on a daily basis) to where we react 100% of the time to the alarms. Alarm fatigue is real.

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We’re on our 2nd CGM receiver and I wish I could get more alarms…we tend to not get actual alarms until he’s in real trouble (hypo wise). I have my low set at 80, but I’ve never heard the alarm go off until it’s in the 50’s.

If you are using the G5, have you considered using a phone to push the signal to you and your wife’s phone via the Dexcom app? That way each parent can have custom alarms set, and I guarantee you will hear them. We keep the receiver in his diabetes bag and use it as a backup, and download it weekly to fill in areas when his phone had drop-out.

I had the phone set up then it stopped working one day and I have had pairing Iissues since then. I’ve followed instructions so not sure why it stopped working for me. I tried uninstalling the app, pairing with a brands new transmitter, etc. I do need to get it working again.

I just tried to reconnect my phone this morning after having not used it for a while and zero success… keeps saying “app encountered an error and needs to close”

It may not just be you…

We use 75 and 130 most of the time. But when we have lots of night peaks the 130 might turn into a 140 or 150.

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Are you guys using the G4 or G5?

G5 Platinum

Hmm, I am stumped then. May want to call Dexcom to help, we have had no trouble getting his phone app and his dexcom to sync.

This is the procedure I would suggest:

  1. take out all bluetooth devices from the settings

  2. uninstall the app (without restarting the sensor)

  3. reboot the phone

  4. reinstall the app

We have had a couple of problems in the past, but this has fixed them. Btw, the dexcom app is bugged on pairing, and you need to reboot the phone and restart the app DAILY to get it to work reliably, or you get signal loss. A pain, I know. My son has a reminder for that every day before going to bed.

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I actually do it all on my phone. There is no xDrip desktop program so the screenshots are from my phone. Saves having to transfer files back and forth so much.

Also, I haven’t even used my desktop for about six months now. I’m totally phone based.

My range is set at 90-250…Since I am constantly looking at it I use this range because that is the range his is usually at. About the alarms…I have bad eyesight without my glasses. That said, night time alarms are always a pain because I have to first locate my glasses–at least that is what I used to do. Now I use a combination of Nightscout and Nightwatch for android. My mounted TV in the master room is set to run nightscout (zoomed in for gigantic number and trend for my crappy eyesight). I use Nightwatch on my android phone as a “follow” device that allows me to get remote reading to my android watch and (most importantly) set unlimited alarms with custom sound files. I have a series of low alarms that say “below 90”, “below 80”, ect so that I don’t have to see anything to get immediate information. The best thing is that they are smart alarms–so if it is trending back up–you wont continue to get those alarms. Plus you can manually set the rising and falling threshold alarms.


We have the receiver alarms set to 200 and 80 — The people at daycare use it and we don’t want it blaring an alarm every five minutes when he’s high, especially because they can’t do anything about it with insulin.

But I have NightScout open on my computer all day long and am monitoring my son’s BG that way. I basically pay super close attention to the rise at certain times of day (lunch, snack), so I see every reading and step in much earlier than 200 after a meal. The rest of the time I mostly rely on openAPS and use the alarms on NightScout (180, 80) to alert me beyond my frequent glancing during the day.

If I was using the alarms on the receiver as the only means to trigger action I think I’d set them to 90 and 130… But I’d also get really annoyed when they were going off constantly.

ETA: At night the low alarm threshold is 90… We will let him drift lower than that of course (even into the 70’s) before treating but in the instance that he’s had a high and now he’s crashing, we want to know before he actually goes low very dramatically.

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