Elegoo water washable resin

[PolkCountyMike]

The information regarding Elegoo water washable resin on Amazon says "6)If you don't use the resin, please do not leave them in the resin tank over 48 hours or put them back to its original bottle and seal it."  This seems to say you cannot put the resin back in the bottle after you have it in the vat.  What do people do who are using this product?  Do you throw away the excess each time?