Many people use the traditional plastic trash can. Provided you cure it, there really is no problem. To do that, fill it with ro water, and add cheep rock salt to take the SG to about what you'd get in your tank. Then let it stand a day or two. Empty, and rinse. Do this several times. If you get any plastic smell, repeat the process. You can also test it by using just RO/DI water, and see if there is any change in the TDS reading over a day or two.