I have this 25l plastic fermenter which is the type not shaped like a big open bucket but with a hole at the top with a screw on lid. I left it full of water not thinking anything bad could happen to it for a few months, and I see now it has a dark mold at the bottom and other type of mold in spots on the side. I'm wondering if I could add a bleach solution to it, then empty it and add clean water and then use it again for brewing, or if it would be impossible to do without bleach being absorbed by the plastic and giving bleach off tastes in future batches etc?
Annoying problem is because I can't get my hand in there like a open top bucket type fermenter its almost impossible to manually scrub it etc..