Hi, Welcome to ECF.
tanks are sometimes hard to take apart if you've gotten a little messy with your
juice and/or tightening it down too hard. Or, it just happens because it happens. LOL.
You can try rubber gloves for increased gripping, if you have an object you can insert in an airhole for leverage in the opposite direction without harming your
tank, that sometimes works, as does running the tank under hot water to loosen things, and a variety of other methods folks use. Hope one of these works.... Just try not to use TOO much force, those ceramic tweezers with a tiny gripper in the middle can be handy too, it's just like those objects to increase leverage for regular jars that can be hard to open.
Welcome to ECF.
Anna