Commercial containers like the ones used for nursery plants work great.. typically somewhere between $1.50 for a #1 (1 gallon) up to maybe $5.00 for a #7.. I've used them over and over for a few years now and doubt I'll have to replace them anytime soon. Investing in heavier drain pans is good too.. I use them for lots of things.. particularly trimming and organizing things in the grow room.