Remaining Tank Water

The next morning there's always some distilled water left over in my tank. Is it okay to reuse, along with new replaced distilled water. I usually ditch the left over distilled water. Wipe the tank clean and replace with new supply of distilled water

Thanks

I often have 1/4 inch or so left. I add new distilled water each night for two or three days and then dump it and start over with all fresh water. The air coming in is filtered twice - first a foam filter and then a very fine paper one but some stuff can get by that I think.
Distilled water is cheap here ($0.98 a gallon) so I am not sure it makes sense to not dump it every night though.

When I used to use distilled water I always topped up. Never had a problem. There isn't enough mineral in the water to accumulate as the water evaporates away. I used to top up overnight for about two weeks giver or take, then wash the tank.

I don't use distilled water anymore. My tap water is pretty soft. With tap water, I do dump and refill as the minerals will start to accumulate. But tap water doesn't have the cost and inconvenience of distilled water.

I don't toss out unused distilled water. When I use tap water or bottled water, I do toss out the unused water each morning.

I don’t refill my water chamber unless it’s like really low or almost empty when I do mine. I try to let it use all the water first.

I throw out what is left in the tank each morning.

Why? Because I am super sensitive to mold and the best way to avoid any hint of it is to keep the tank dry for about 12 hours a day. Because there is (a very remote) risk that something else bad could grow in there. And, finally, because the benefit of reusing the residual water is small -- I use an extra two to three liters of distilled water per month because I throw out the residual.

i use distilled water and i throw away every morning and let my tank open to air dry.

i also unplug my hose from the machine and let it hang.

not sure if this is over kill or not but i feel better when the machine and all pieces stay dry when not in use.

at any rate makes me feel better.

I used to keep it in the tank. Then visited vietnam, and stuff was definitely growing in there (Even with the distilled water, and the double filters in a PR system). Even if not moving (yet) there was life.
So now I'd dump it, even at home - only in the past few months the tank was always empty and dry in the morning.

I always just top off the water chamber the next morning and I've never had an issue (when using distilled water).

I did an experiment and confirmed the first water used by the humidifier is the water that was left from the night before, so I just top it off every night.
Every month or 2 I will swish some tap water in the chamber to sterilize it. Every year or 3 I will use a new chamber.
With my original S9/H5i I sometimes had trouble distinguishing the old chamber from the new one. With PR it was easier to tell, with my new Resmed Aircurve, I haven't had it long enough to notice.
I do use Reverse Osmosis water so I don't worry about bottles or cost.