Dry mouth, chapped lips, little or no leaks, with a maxed out humidity setting & heated hose

[robysue1]

Folks,

Those of you who've been around know that I'm a long time PAPer. In November 2022 I switched from a PR DreamStation BiPAP Auto to a Resmed Aircurve 10 VAuto. I wrote about the early experiment days with the AirCurve in this thread.

I've now been using an AirCurve for 2 1/2 months. I started playing around with the heated hose a while back. I was dealing with my standard winter-time problem of occasional rainout accumulating in the part of the hose that sags between the machine and the edge of the bed where I run the hose (in a hose cozy) under the covers, along with a fairly common "wet puppy dog nose" problem caused by condensation in the nasal pillows, which doesn't really bother me that much anymore. I thought (correctly) that the heated hose might help with the rainout and the wet puppy dog nose problem.

But since I started using the heated hose, I've started to experience some dry mouth problems, which are new, combined with a return of the old chapped lip problems that have plagued me off and on since I first started PAPing back in 2010.

The problem has been slowly growing worse during January, and by a few nights back, the dry mouth problems had become pretty severe: I was waking up with a super dry mouth during the night and having to drink water before I could get back to sleep and by January 20th, my mouth was feeling dry throughout most of the day even though I've been trying to consciously increase my water intake. The inside of my nose has been dry and sore and congested during the daytime most of this month, and the chapped lips are noticeable, but not yet severe. Things finally got so bad with the dry mouth problems that I turned the hose off a few nights ago.

Here's the relevant information about my settings and my bedroom environment when I was using the heated hose:

• Min EPAP = 4 cm
• Max IPAP = 9 cm
• PS = 4 cm
• Hose Temp = 67F
• Humidity setting = 8 (max)
• Bedroom temp in the low 60s
• We have a whole house humidifier attached to the forced air heater; ambient relative humidity in the house stays around 40%
• The humidifier tank is not running dry during the night; I fill it to the max line at the beginning of the beginning of the night, and it's usually at or just above the 1/4 full line when I wake up in the morning.

And my data shows little or no leaks on the typical night. Here's the Oscar data from the last night where I had the heated hose turned on:



As you can see, there's no evidence of any significant leaking. So I don't think my dry mouth problems are caused by mouth breathing. And since the aerophagia has not raised its ugly head, I'm pretty sure that my tongue is staying put on the roof of the mouth most of the night. But maybe the fact that I've made a conscious effort to avoid eating too close to bedtime is helping to keep the aerophagia away even if my tongue is allowing some air into the mouth by not staying parked up where it should be.

My mouth was so painfully dry after the night of Jan. 23 that I turned the hose temp to OFF in the hope that maybe that would help. Since turning the hose temp OFF, I have noticed some (small) improvements in the dry mouth problem, the nose is a bit happier, and the lips are about the same. But the rainout problems have returned, along with the wet nose. And I am still waking up at night thirsty with a rather dry mouth, but it's not as bad as it was during the last week I used the heated hose.

Back during my first winter of PAPing I had a lot of these problems, but I don't remember the dry mouth being as severe as it's been this month. I do remember using Biotene mouthwash back then and it helped a bit. I think may also buy some Xylimelts.

But what I'd like to pick folks brains about these questions:

1) Is the AirCurve's humidifier a "smart" humidifier that attempts to prevent rainout even when you're not using a heated hose? I ask because during the last several years I typically had my PR DreamStation humidifier set to Classic 5, which is the maximum setting in the non-smart mode. Yes, I dealt with some occasional rainout problems and some pretty common wet puppy-dog nose problems, but I didn't wake up with a super dry mouth all the time and my nose wasn't painfully dry during the daytime. But switching to "smart mode" would make my nose less happy.

2) Any ideas on why my nose and mouth seem to be getting more dried out when I have the hose temp set to 67F than when I have the hose turned off? A lot of folks here routinely tell people who are complaining of dry mouth problems or dry noses to not only turn the humidifier up, but also turn up the hose temp. Well, I can't turn the humidifier up anymore, and increasing the hose temp seems to have aggravated my dry nose and dry mouth problems. Or maybe my nose and mouth care more about getting the relative humidity as close to 100% as possible instead of having a higher temperature that would allow a higher absolute humidity, but lower relative humidity in the air coming through the hose.

3) Would turning the hose up past 67F increased the the absolute humidity in the hose air in order to maintain a constant target relative humidity in the hose air? I never turned the hose temp above 67F because I really don't like hot, humid air. I have always had trouble sleeping in rooms with an air temperature in the 70s, so the idea of really cranking the hose temperature up to the 80s in an effort to get additional humidity isn't very appealing.

Well it's past my bedtime. So I'm going to see if I can find some Biotene stashed somewhere in the bathroom and use it tonight to see if that helps.

[Albatros]

Robysue, many thanks for your thread, very interesting.
Even if, still a 4 months beginner, don't understand every detail.

If I make a modest comparison with my case.
For a AHI comparable:
-your FL is very good, mine is awful (0.13 to 0.18)
-you have an aerophagy problem, I don't
therefore my settings are different from yours. PMax 19, Pmin 10, EPR 2.

I find that my nights are, on average, much quieter than yours, but this is probably related to your test phase of the machine.

I still have some beginner questions:
Your setting Pmax 9, Pmin 4.
PS = 4 ? What is this?
You don't mention the EPR ?
You have two lines for the pressures on oOSCAR, I only have one?

Thank you

[jlsmithseven]

I've been having similar problems and I can vouch for the Xylimelts they have been helping me a TON.
As far as BIOTENE Mouthwash, they changed their formula and sold the company. The same ingredients are now with a company called Salivia. I've got a bottle and it works much better than any Biotene products I've tried recently. I use the Salivia each night along with Xylimelts and it helps my dry mouth. I have everything on AUTO with tube.

[robysue1]

If I make a modest comparison with my case.
For a AHI comparable:
-your FL is very good, mine is awful (0.13 to 0.18)
-you have an aerophagy problem, I don't
therefore my settings are different from yours. PMax 19, Pmin 10, EPR 2.

So you are using a Resmed AirSense Auto PAP.

I find that my nights are, on average, much quieter than yours, but this is probably related to your test phase of the machine.

Most likely you have less wakes than I do because you have better sleep. I have multiple sleep problems in addition to the OSA. Namely, I've been battling sleep maintenance insomnia and a I have a so-called delayed sleep phase problem for years. The combination of these two problems is why I have so many wakes and why my bedtimes are so late.

Still, I now sleep better than I was before starting xPAP. On a typical morning I wake up feeling rested and, more importantly, I wake up pain free.

I still have some beginner questions:
Your setting Pmax 9, Pmin 4.
PS = 4 ? What is this?
You don't mention the EPR ?
You have two lines for the pressures on oOSCAR, I only have one?

You are using a Resmed AirSense Auto PAP. I'm using a Resmed AirCurve VAuto PAP.

In other words, I'm using a so-called bi-level machine. Bi-levels are often, but somewhat inaccurately called BiPAPs---BiPAP is the Philips Resprionics name for their bi-level machines.

PS is the pressure support setting, and it's the difference between my so-called IPAP pressure and EPAP pressure. The IPAP pressure is the pressure the machine goes to when I am inhaling; the EPAP is the pressure when I am exhaling. On my pressure graph, the top line is the IPAP graph and the bottom line is the EPAP graph.

Your EPR setting is very similar to the PS setting on a bi-level machine, but EPR is limited to a maximum of 3cm. On a AirCurve VAuto, the PS is not limited, but in practice most people using an AirCurve VAuto have PS set something around 4-6cm; much more than than can cause problems with central apneas for a lot of people and a PS higher than 6 doesn't usually improve either comfort or the AHI. Bi-levels require a script that specifies a bi-level machine. People usually wind up with a bi-level when they either "fail" CPAP/APAP due to problems like aerophagia or they need higher pressure than a CPAP/APAP can deliver. (An AirCurve VAuto can go all the way to 25cm of pressure instead of just 20cm.)

There's another kind of machine called an AirCurve ASV, which has variable PS, and typically the max PS is set significantly higher than the min PS. The idea with the ASV machines is that when the machine detects a breathing pattern that can lead to a string of central apneas, it steps in by triggering inhalations through a massive increase in PS (and hence IPAP) on the inhalations while leaving the EPAP rather low.

[ozij]

And my data shows little or no leaks on the typical night. Here's the Oscar data from the last night where I had the heated hose turned on:

No leaks, but you're snoring before you wake up.

https://www.resmed.com/en-us/sleep-apne ... umidifier/

That’s why we include Climate Control Manual mode in your ResMed AirSense™ 10, AirCurve™ 10 or S9™ CPAP/VPAP machine – so long as you also have a ClimateLine™ or ClimateLineAir™ heated tube. Here’s how it works:

In other words, the humidifier and climateline functions the same for the whole AirX series.

They also have the following there:

When should I change the humidity vs. the temperature?
Most patients find cooler air easier to breathe while trying to sleep, especially those who are new to CPAP, wear a full face CPAP mask, and women experiencing hot flashes at bedtime. However, warmer air provides the best humidity and helps reduce nasal irritation since your nose doesn’t have to warm all that CPAP air on its own. It generally helps to increase:

Humidity if dry air is causing you to wake up with dry mouth, an uncomfortable side effect that 40% of CPAP users experience.1 If you want more humidity, try manually adjusting it and the temperature one notch at a time. If you reach the highest levels and still feel dry, talk to your equipment supplier and doctor about whether mask leak, oral medications or other factors may be the real cause of your dryness. (You should also check for mask leak if you wake up to find your humidifier’s water chamber empty.)
Tube temperature if you’re experiencing dryness despite increasing the humidity. Consider increasing your tube temperature by just 1–2⁰F to see if that provides the best comfort.

[my emphasis]

I think you should keep in mind that the nose is biological system, not an inert tube. One of its physiological roles is to warm the air you breathe before it gets into your lungs.

By keeping the hose temp lower, you actually making life a bit harder for your nose - don't go just by what you know of your response to heated room air. Try the effect of heated, more humid air on your nose, empirically.

[robysue1]

I've been having similar problems and I can vouch for the Xylimelts they have been helping me a TON.

Thanks for the recommendation. I think I will try Xylimelts.

As far as BIOTENE Mouthwash, they changed their formula and sold the company. The same ingredients are now with a company called Salivia. I've got a bottle and it works much better than any Biotene products I've tried recently. I use the Salivia each night along with Xylimelts and it helps my dry mouth. I have everything on AUTO with tube.

I'll keep this in mind. The bottle of Biotene that I have is several years old and it seemed to help a lot last night. I'll keep an eye open for Salivia.

[Albatros]

If I make a modest comparison with my case.
For a AHI comparable:
-your FL is very good, mine is awful (0.13 to 0.18)
-you have an aerophagy problem, I don't
therefore my settings are different from yours. PMax 19, Pmin 10, EPR 2.

So you are using a Resmed AirSense Auto PAP.

I find that my nights are, on average, much quieter than yours, but this is probably related to your test phase of the machine.

Most likely you have less wakes than I do because you have better sleep. I have multiple sleep problems in addition to the OSA. Namely, I've been battling sleep maintenance insomnia and a I have a so-called delayed sleep phase problem for years. The combination of these two problems is why I have so many wakes and why my bedtimes are so late.

Still, I now sleep better than I was before starting xPAP. On a typical morning I wake up feeling rested and, more importantly, I wake up pain free.

I still have some beginner questions:
Your setting Pmax 9, Pmin 4.
PS = 4 ? What is this?
You don't mention the EPR ?
You have two lines for the pressures on oOSCAR, I only have one?

You are using a Resmed AirSense Auto PAP. I'm using a Resmed AirCurve VAuto PAP.

In other words, I'm using a so-called bi-level machine. Bi-levels are often, but somewhat inaccurately called BiPAPs---BiPAP is the Philips Resprionics name for their bi-level machines.

PS is the pressure support setting, and it's the difference between my so-called IPAP pressure and EPAP pressure. The IPAP pressure is the pressure the machine goes to when I am inhaling; the EPAP is the pressure when I am exhaling. On my pressure graph, the top line is the IPAP graph and the bottom line is the EPAP graph.

Your EPR setting is very similar to the PS setting on a bi-level machine, but EPR is limited to a maximum of 3cm. On a AirCurve VAuto, the PS is not limited, but in practice most people using an AirCurve VAuto have PS set something around 4-6cm; much more than than can cause problems with central apneas for a lot of people and a PS higher than 6 doesn't usually improve either comfort or the AHI. Bi-levels require a script that specifies a bi-level machine. People usually wind up with a bi-level when they either "fail" CPAP/APAP due to problems like aerophagia or they need higher pressure than a CPAP/APAP can deliver. (An AirCurve VAuto can go all the way to 25cm of pressure instead of just 20cm.)

There's another kind of machine called an AirCurve ASV, which has variable PS, and typically the max PS is set significantly higher than the min PS. The idea with the ASV machines is that when the machine detects a breathing pattern that can lead to a string of central apneas, it steps in by triggering inhalations through a massive increase in PS (and hence IPAP) on the inhalations while leaving the EPAP rather low.

Thank you

[robysue1]

And my data shows little or no leaks on the typical night. Here's the Oscar data from the last night where I had the heated hose turned on:

No leaks, but you're snoring before you wake up.

Intermittent snoring, mostly right before I wake is something that I've learned to put up with: The snores are not loud (according to my husband) and it doesn't happen every night. And the pressure needed to eliminate the last bit of snoring every single night leads to aerophagia and no real improvement in how I feel during the day.

https://www.resmed.com/en-us/sleep-apne ... umidifier/

That’s why we include Climate Control Manual mode in your ResMed AirSense™ 10, AirCurve™ 10 or S9™ CPAP/VPAP machine – so long as you also have a ClimateLine™ or ClimateLineAir™ heated tube. Here’s how it works:

In other words, the humidifier and climateline functions the same for the whole AirX series.

They also have the following there:

When should I change the humidity vs. the temperature?
Most patients find cooler air easier to breathe while trying to sleep, especially those who are new to CPAP, wear a full face CPAP mask, and women experiencing hot flashes at bedtime. However, warmer air provides the best humidity and helps reduce nasal irritation since your nose doesn’t have to warm all that CPAP air on its own. It generally helps to increase:

Humidity if dry air is causing you to wake up with dry mouth, an uncomfortable side effect that 40% of CPAP users experience.1 If you want more humidity, try manually adjusting it and the temperature one notch at a time. If you reach the highest levels and still feel dry, talk to your equipment supplier and doctor about whether mask leak, oral medications or other factors may be the real cause of your dryness. (You should also check for mask leak if you wake up to find your humidifier’s water chamber empty.)
Tube temperature if you’re experiencing dryness despite increasing the humidity. Consider increasing your tube temperature by just 1–2⁰F to see if that provides the best comfort.

I can't increase the humidifier setting since it's maxed out at 8. So that only leaves increasing the hose temperature. Since my bedroom temp is in the low 60s, using a Hose Temp = 67F is about a 5F increase in the air temperature in the hose over using an unheated hose.

But my nose doesn't seem to have read the Resmed memo about higher temps: My nose (and mouth) seem to be much dryer when I use (Humidifier = 8 and Hose Temp = 67F) than when I use (Humidifier = 8 and Hose Temp = Off).

I think you should keep in mind that the nose is biological system, not an inert tube. One of its physiological roles is to warm the air you breathe before it gets into your lungs.

By keeping the hose temp lower, you actually making life a bit harder for your nose - don't go just by what you know of your response to heated room air. Try the effect of heated, more humid air on your nose, empirically.

The ambient temp in my bedroom right now is in the low 60s. Adding heat to increase the hose temp from about 62F to 67F increased the dry nose & mouth problem.

So my question is still this: Will the humidifier actually add more water vapor to the air if the hose temperature is increased beyond 67F? In other words, will the absolute humidity in the hose go up even though the relative humidity will decrease from close to 100% to something that is low enough to prevent rainout, which seems to be the real reason heated hoses were invented.

I suppose that a further experiment with a potentially much higher hose temp may be worth it. The question is do I just increase 1 or 2 degrees F at a time or do I go whole hog and jump to something higher than 67 to begin with? If I go whole hog, what's a reasonable starting point for the hose temp?

[lazarus]

In harmony with what Ozij has posted, I would slowly raise hose temp one or two degrees at a time much like any other treatment-parameter experiment.

As I'm sure you are aware, any increase in air temp will allow the air to hold more absolute humidity at a given relative humidity setting. So as your body heats up the cold air, it in a sense makes the air dry. Allowing the temp in the hose to be even slightly higher, you allow that air to hold more moisture. Similarly, allowing the air in the house to be warmer allows more moisture in the air at that 40% relative humidity setting. If you aren't causing condensation on the inside of your cold windows during the heart of a Buffalo winter, you are breathing dry air all day.

Dry, cold winter air is a test for many who spend any time outdoors or in locations other than a climate-controlled home. Upping hydration by simply drinking more water to compensate can help.

Maybe instead of thinking of comparing the temperature of the air in the hose to what temperature of air you normally find comfortable for the ambient temperature surrounding you in a room, think of the hose air as an extension of your respiratory system, which operates at body temperature and works very hard to stay moist.

Eating less food before bed means you are taking in less liquid content from the food, so drinking more during those hours can help. Medications, even ones as simple and common as caffeine and alcohol, can effect mouth dryness, especially at night, and winter can exacerbate those effects.

I wish you all the best as you look for your correct formula for solving for x.

[robysue1]

As I'm sure you are aware, any increase in air temp will allow the air to hold more absolute humidity at a given relative humidity setting. So as your body heats up the cold air, it in a sense makes the air dry. Allowing the temp in the hose to be even slightly higher, you allow that air to hold more moisture.

I'm aware of the physics: It takes less added water vapor to reach a relative humidity of close to 100% when the air temp in the hose is 62F than it does to reach a relative humidity of 85% when the air temp in the hose is 70F.

What I'm wondering about is the machine's programming: When the hose temperature is increased, is the humidifier programmed to add more absolute humidity (i.e. more water vapor) to the air than when the hose is turned off?

In other words, if I increase the hose temp to 70F, does the machine know to add more absolute humidity (i.e. more water vapor) in order to get the relative humidity inside the hose up to something close to 80 or 85%?

Or when the hose temp is increased, does the humidifier add the same amount of absolute humidity (i.e. water vapor) to the air with the expectation that the lower relative humidity will prevent rainout from occurring?

Similarly, allowing the air in the house to be warmer allows more moisture in the air at that 40% relative humidity setting. If you aren't causing condensation on the inside of your cold windows during the heart of a Buffalo winter, you are breathing dry air all day.

Given that I've lived in the Midwest and Buffalo for my whole adult life, I know all about how dry forced air heat is as well as just how dry the outside air is even when the outside air is saturated at 100% humidity.

We keep the humidity setting on the whole house humidifier just below where we start to get condensation: We had problems with water vapor condensing on exterior walls in one of the apartments we lived in back in Illinois and the result was a substantial mold problem and we filed a formal complaint with the Landlord Police to force the landlord to install some exhaust fans and treat the mold.

Dry, cold winter air is a test for many who spend any time outdoors or in locations other than a climate-controlled home. Upping hydration by simply drinking more water to compensate can help.

As someone who genuinely likes water, I usually drink copious amounts of water and I'm currently trying to pay a bit more attention to my water consumption to make sure I am drinking enough water.

Maybe instead of thinking of comparing the temperature of the air in the hose to what temperature of air you normally find comfortable for the ambient temperature surrounding you in a room, think of the hose air as an extension of your respiratory system, which operates at body temperature and works very hard to stay moist.

While I understand the idea here, I also know that my whole body is not fond of trying to sleep in warm conditions. That's why we keep the house so cold.

And for what it's worth, we have to keep the AC on at 68 or below at night in the summer just so I can sleep: Any setting higher than that, and I'm tossing and turning all night long in part because the air in the hose feels way too warm when the AC is set to a more reasonable 72. And when I visit relatives who keep their AC at 78, I'm absolutely miserable all night because the CPAP air makes me feel even hotter than I do before I lay down.

Eating less food before bed means you are taking in less liquid content from the food, so drinking more during those hours can help.

While I try to quite eating to minimize stomach problems, I keep drinking water right up till I climb in bed.

Medications, even ones as simple and common as caffeine and alcohol, can effect mouth dryness, especially at night, and winter can exacerbate those effects.

I gave up caffeine years ago in the First War on Insomnia. Yeah, I back slide now and then by allowing myself caffeinated iced tea at lunch, but that's about it in terms of caffeine.

As for alcohol, I'm a very occasional drinker---as in I typically go several weeks between drinks. About the only time I have any alcohol these days if if hubby and I go out to eat dinner without my alcoholic cousin who lives with us.

Medication is interesting: I am on a glaucoma eye drop right before bedtime. And I continue to take Deplin (which is a megadose of the metabolized form of folate) and Vitamin B2 in order to keep the migraines at bay. But that's it.

I wish you all the best as you look for your correct formula for solving for x.

Thanks.

At this point I think I am going to have to experiment with increasing the heat in the hose.

But I'm still faced with the fact that turning the hose temp to 67F was a de facto increase of 5 degrees in the temp of the air in the tube, and that 5 degree increase in hose temp has led to more of a problem with dryness rather than less of a problem. And the fact that I've been more dry with the higher hose temp is counterintuitive. That's why I'm wondering just what the machine's humidifier is actually programmed to do in terms of how much absolute humidity it adds to the hose air when the humidifier is set to 8 and the heated hose is being used as well as what the machine's target relative humidity might be when the humidifier is set to 8 and the hose temperature is set to x degrees.

[lazarus]

I don't claim any expertise, but my understanding is that once you are in Manual mode, it isn't about programming or anything the machine does. It is only about the physics principle that warmer air can hold more moisture to take advantage of your already maxed out heat plate at the bottom of the water chamber.

Of course, keeping the hose at a constant temperature only makes it possible for that air to carry more moisture. There is no provision to preheat the air before it enters the machine. So, much depends on the temperature of the air in the room, which limits the moisture you are starting with and the possibilities of success in altering it. No amount of machine programming or settings can overcome those limits of the laws of physics that determine the success of one's manual settings.

In other words, if your manual setting for heating the warming plate is already maxed out, then the only parameters left are (1) increasing tube temp, (2) increasing room temp, or (3) increasing relative room humidity.

The balance between high-desert dry and mold-filled walls can lie along a razor's edge in modern sealed buildings. The old days of a potbelly stove with a pot of water evaporating at the top and leaky cracks between the logs in the walls may have been a simpler, healthier time in some ways. But I'm happy to be alive in the era of PAP instead, despite the sometimes frustrating limits of present PAP technology.

I realize I could still be missing the point. Sorry about that. I am a longtime card-carrying Captain Obvious, and old habits die hard.

I might be more helpful had I not dumped my heated hose. In my case, a hose cover was enough to prevent rainout in my lightweight slimline tubing.

Hopefully more experienced ones will chime in with actual experience.

[ozij]

In other words, if I increase the hose temp to 70F, does the machine know to add more absolute humidity (i.e. more water vapor) in order to get the relative humidity inside the hose up to something close to 80 or 85%?

Yes

That's why I'm wondering just what the machine's humidifier is actually programmed to do in terms of how much absolute humidity it adds to the hose air when the humidifier is set to 8 and the heated hose is being used as well as what the machine's target relative humidity might be when the humidifier is set to 8 and the hose temperature is set to x degrees.

Resmed's table for target humidity when climate control is on manual

The ResMed climate control system has an ambient temperature sensor. I'd run the basic experiments without covering the hose.

At the default hose temperature, the hose heats up quickly, and is pleasantly warm when you touch it.
If the doesn't happen, then I'd try disconnecting and reconnecting it, and if it still doesn't heat, I'd clean the connectors with alcohol.

Personally, I I find there's no relationship between the air temperature I find pleasant for my nose and the room temperature in which I find it impossible to sleep in summer.

[Albatros]

Robysue,

Can I ask you a very timid question about your struggle with condensation/humidity.... ?

I sleep in a room at 17 degrees celsius/62.6 fahrenheit, humidifier of the Airsense 11 set at 2, hose kept outside.
It is not an issue for me.

What would be the result for you?

[lazarus]

humidifier of the Airsense 11

Robysue is using a Resmed Aircurve 10 VAuto.

[jlsmithseven]

In terms of your question whether the hose temp changes relative humidity, I believe in my research it does if Humidity is kept on Auto setting. Basically, the Tube Temp setting is independent of the Humidity setting in that you are allowed to choose whatever temp you want for the hose and if you keep Climate Control on AUTO it keeps humidity in the tube to the 80% or so humidity. Now sure how it is on the Aircurve 10 but I believe it's the same.

But I keep my room around 68-70 degrees year round and I've tried messing with Tube Temp and Humidity settings and I just can't get it right. I usually end up getting rain out or way too warm air. I keep everything on AUTO and as long as I control mask leaks it works fine for me. But again that is me. I actually like warmer air but I've given up trying to find the right settings. Because of the night variability in winter time it's hard to find the right adjustments so I let the machine calculate it all night.