I have been browsing craigslist regularly for anything from animals to equipment to discarded plastic drums for water tanks. After doing some extensive math that will be included in a future series of posts, I quickly realized that the rainwater collection system would be best served with a higher capacity than 55 gallon drums could accommodate reasonably.

Off to Craigslist in search of some of the 250+ gallon tanks that come in metal cages, pictured below.

Water Tank

First for the warning: Like 55 gallon plastic drums, be VERY particular to source a tank that stored food materials or safe chemicals. Watering animals, plants or yourself with water tainted by industrial-grade acid, chemicals, etc would be tragic and entirely avoidable.

Advice: Don’t write off tanks with chemical stickers like I almost did. Luckily the craigslist ad for 300 gallon tanks had a price that made me inquire despite almost dismissing the option due to visible chemical stickers on the tanks. Here is a picture from the ad:

Turned out the tanks contained medical grade Hydrogen Peroxide. The seller of the tanks explained that he does not clean them out as the solution keeps the inside of the tanks sterile. All that is needed to make them food-safe is to add 10 gallons of water, slosh it around and dump it out as the trace amounts of it have been diluted to ~1% and will break down into water + oxygen gas once exposed to light.

Self-sanitizing 300 gallon tanks at twice the local going rate for 55 gallon drums? I took as many as I could safely haul at once and may go back for more. They would make the perfect mobile watering tank for cattle, rain barrels or even a tank to combine smaller rain water containers together! Also I am sure they could be used to barter with other farmers/gardeners if I find myself with too many in the end.

To recap, when sourcing potential water tanks, be very careful to determine exactly what they held previously. If they were used for non-food uses, see if there is a way to make them food safe before writing them off. After all I much prefer my Hydrogen Peroxide container to the cleaning I’ve done in the past to an agave or honey container!