Or even pond lining material
Best place to buy planting tubs for water lillies and lotuses
I use the black tubbies from the pond department at Lowes. They're only $11 and are thick black plastic/rubber.
Feed and seeds usually have big selections of watering troughs. Check rural stores and Tractor Supply. They have a web site so if you see something there you might be able to comparison shop it locally.
I won't be ashamed to admit ( well sort of!) that I have used the oil change black tubbies from the dollar store....as well as the black trash cans (small bathroom type) from the dollar store, too! :)
Lowes has a larger black tubbie in their pond department for $11. I use them for everything from water lily starts to fish fry raising. So affordable.
MacCourt 9-Gallon Black High Density Polyethylene Pond Liner,they have these listed for $9,95,little larger than I need ,more like 3 to 5 gallon size,thanks