First I know that's Echo and my experience with this type of issue was GO-GO but the cartos are of the same type design, so here goes. I have said often I use 4 plus ml a day of juice. It just so happens my "go to" is Tasty Vapor Atomic Cinnacide which I mix 50/50 with DK-Tab.
What many have experienced is that the ejuice vendors who use a high "sugar-type" content not only gunk up cartos but attys and any thing else they get on more quickly than other juices. Tx and others can get weeks out of a carto but I get like 4 - 5 days max before they have to be rebuild type cleaned.
In my experiences, when I have gotten the "muddy" juice out the bottom, it is because the coil was so caked up that running hot water through them and drying them only softened up some of the layers of gunk on the coil. I have had one case where I was still getting fair vapor but got the muddy juice out the bottom and wicked bad taste. Since I use a high PG/VG ratio, 85/15, I figured the one odd time that the PG had knocked some gunk of the coil.
Disassembling proved that to be correct. The one thing I like about the Mohawkz Method of rebuild cleaning is that you dry burn the coil just like a regular atty and when reassembled, you have a carto that 99% of the time works like new. The only key is to determine what is the max usage time for you based on your vaping habits and type of juice used.
If you don't have the time nor patience to do that type of cleaning, several have had good luck with an inexpensive Ultrasonic cleaner. I have one but haven't ever used it with the good luck I am having doing the long route. No other carto type offers me the capacity and consistent vape I get with these fat battery/large horizontal coil cartos so it's worth it to me.
All I can suggest is the next new carto you start using, note the vapor production and how long it takes for it to begin tapering off with your juices of choice. When it really starts dropping and you know you have juice in it, set it aside for cleaning no matter your chosen method and go to another. It
will vary. Although it doesn't satisfy my cravings alone for example, I can use 100% DK-Tab and get almost 2 weeks from a carto. Pure Atomic Cinnacide and I wont get 4 days.
Sorry for the wall of text but with all the different formulas juice makers use and the different ways we use our PV's, there is no set pattern as to when other than the reduction in vapor you feel warrants action. How you vape matters too! Like Tx didn't even know his had a cutoff on the draw due to his way of vaping. Me, I just know to let up on the button when the led starts flashing because I wont be getting more vape until I re-press the power button.
