Needed a new place for some guppies... they exploded once I planted my aquarium!
Saw this, and thought... perfect solution! (until winter arrives... hmmm)
Went to Lowes, got a whiskey barrel repro like Church mentioned. It's only 15 bucks. It's all one piece. It has no "drain plug" in the bottom... so it is watertight. The barrel is small, it only holds about 12-15 gallons.
Got a bag of pea gravel. 4 bucks. Got 4 pond plants (red lily, mare's tail, water parsley, corkscrew rush?) all on sale now at Lowes! Less than two bucks each.
Grand total... $26.
Dumped some pea gravel on the bottom. Did a partial water change in my aquarium (was due)... and pulled out all the anacharis that was beginning to over grow and shade it. Also some small bits of golden pennywort, and baby tears and java fern made their way in also.
Used the 5 gallons of aquarium water as "starter" for my barrel. Then filled the barrel. Put the pond plants in. Water was quite cloudy from the pea gravel (didn't wash it...). Looked markedly better this morning. I'm guessing it'll be fine in a day or two.
Looks decent to me already. Can't wait to see what happens to my low tech outdoor planted tank! LOL