I have a couple rubbermaid 100's I'd sell. At first I had trouble propagating daphnia in them ( a small shrimplike freshwater invertebrate) but after they stabilized they worked fine. If you get new ones, I'd rinse them a lot or season them even better. they are perfectly safe for horses and cattle to drink from, probably us too, but very sensitive inverts might react to whatever plasticizers leach out for a while. I also have a big blue vat that is much bigger and was used to process frozen food.