I water my garden with well water & it is pretty cold even thru the summer.
I made this stand & 2 - 55 gallon drums. Elevated enough for gravity flow & tipped forward a few degrees so they drain almost totally empty for the winter.
I cut a small hole in the top rear high spot for filling & an air vent.
The black absorbs heat during the day. Plumbed to hoses & valves to various spots in the garden. Sure help to water plants with 60 to 80 °f water instead of "shocking them" with cold well water. I can also mix fertilizer if needed & water the whole garden with the 110 gallons of warm water. I also have a hose into the GH for watering there too.
Every now & then I spray paint the blue one with flat black paint.
Tied them down after a winter wind blew them off & broke all the plumbing.
Learned to empty them & leave all valves open & drained thru the winter too.
I used good thread sealant for the fittings , a slow leak can empty them in a few days.
I fill them with the same hose that goes to the GH (back flow) & learned to put a piece of yarn on the fill valve that goes on my finger when I open it. (a few hours of overflow are messy )