Dry mouth

I wake up during the night with dry mouth I have the resmed airsense 10 bipap machine I-have a full face mask and even use a chinstrap also drink plenty of water during the day I also have adjusted the humidity level on the machine from 3 to 5 and still have extremely dry mouth when I go to 6 on the settings water gurgles in the tube leaking into the mask. My hose is a climate controlled hose. What can I do to fix this problem I also went back to the VA for them to check out my machine.

If you are breathing through your mouth, it will cause dry mouth. If this is the case, try either a chin strap or a firm, foam cervical collar.

I use a chin strap and also a full face mask.

Unfortunately there are some people who get dry mouth for any number of reasons.
Mouth breathing is of course one reason but not the lone reason. Some people might be taking medications that tend to dry out the body. Some people just drew the short straw and their mouths don't produce a lot of saliva and the least little bit of mouth breathing or whatever will cause dry mouth. Some people have other health issues that cause the mouth to dry out.

Adding more moisture by increasing the humidity level of the cpap machine sometimes will work and sometimes won't help and of course can cause rainout in the mask or hose as a side problem. If you are using a heated hose and you have the hose air temp masked out and you are still getting condensation in the mask or hose then not much you can do unless you do something else to try to prevent the condensation and choices are usually limited anyway with no guarantee that it will help.

A lot of people will choose to just add some sort of moisturizing agent to their mouth in an effort to keep the mouth more moist.

Some people get terribly dry mouth and they don't mouth breathe because they tape their mouths shut. Just unlucky.

If you haven't maxed out the hose air temp to enable you to add more moisture via the cpap humidifier then that is one option you might have.
If you have already done that then maybe look at some sort of moisturizing oral product to add moisture to your mouth.

Some people benefit from Xylimelts, which are small discs that stick to your teeth or gums and stimulate the production of saliva throughout the night.

In my case, I tried the above suggestions without effect. I went to mouth taping and it has solved the problem, using the MedVance 2" wide silicone tape available on Ama***. It does not pull off a layer of skin when removing in the morning. YMMV.