I always make sure to never refill a cart twice- smoke it until the amount left is suitable to make the proportions you want- then toss it when it’s done. I’m afraid of burning the cotton, visible on the fake carts i get although the same type of cotton is inside the cartridges made by Rove which I have been getting legitimate, legal carts.
The cartridge that’s half Pink has a THC-to-CBD ratio of ~1:2 (?) or about 1/3 THC. The other cart that has a green mouthpiece and bottom is much stronger- probably 50/50 (1:1?) 
Here is a shot of my newest favorite brand- Rove, which is not counterfeit. Roves are harder to counterfeit because they’re only available in California and Nevada, meaning you can rule out any nevada carts since they cost 10x more. Also, real roves come with an ugly third party sticker which displays a pot leaf and an exclamation mark, with letters CA underneath- all in a pyramid. If it says CA! then it is fake. This sticker has several ID numbers for users to locate the exact dispensary the Rove came from {in Cali}. Im worried I’ve been smoking shit i really should not ever since switching to Rove which can back up their “solvent free” claims, something counterfeit carts can’t and i don’t think do- considering the immense different in the smoothness of the hit, and temperature of vapor. It never makes me cough.
Welcome to weedcash bro! https://www.weedcash.network/oilcartridges/@novus-locus/cbd-thc-mixed-oil-carts-rove-and-counterfeits there is the link to see your post on the weedcash front end.
Damn i never really thought about fakes. Crazy. I bet it is a big problem.