Hi Tony, you can filter it back in to the tank or cartridge with 190 micron (or finer) automotive paint filters and a funnel.
This will trap any debris such as dust and dirt that have made their way in to the resin and also any partially cured resin from fails or peeled layers that may have detached during printing.
Apparently its not recommended to keep the resin in the tank for too long (we’re talking weeks to months I believe) as it can cause the clear, rubbery layer to detach from the tank base. In this case take it out of the tank and store it somewhere dark or filter it back in to the cartridge.
If I understand correctly you want to save the resin stuck on the print and BP after the print is finished ? If so take a look at that :
Doesn’t work for the tallest prints but worth a look.
If your print doesn’t have any minima you should really not get any bits to filter, and I would pour the resin straight back into the tank. I don’t care about the resin stuck on the parts, but if I print a small part I still use the scraper to scrape off the resin stuck on the BP and pour is straight into the tank (from the BP, I scrape gently so at to not put aluminium bits into the tank).
In case you really want to pour into a container, then back into the tank, then use a black, opaque container with a somewhat airtight lid and you won’t have to store the container in a dark room
I’ve found it is really important to filter any resin left on the build plate if you use mini-rafts and an LT tray. The bases of the mini-rafts tend to break off and get mixed in with uncured resin. If this resin is not all removed you can get these small discs causing permanent depressions in the LT tray’s base coating.