Insulating outdoor caged water holding tank

[Bessie7881]

Hello, what are the best methods used for insulating an outdoor, square caged water hold tank?

[LMHS]

Get a waterbed heater and put it on the bottom against the plastic tank. They are made to not melt vinyl so it will be safe for the plastic tank. I would suggest that you use a layer of reflectix against the tank and then use a couple layers of 2" rigid house foam (the colder it gets, the more insulation you will need). They make a special glue just for "foamboard" that you can find at Home Depot, amongst other places. This is what we did with a cistern for the spring that was next to our pump house. We used 4" of foam in the Southern Appalachians which was probably overkill for our area.

[Lwiddis]

Using "with an electrical heating element" is the safest way even with lots of insulation.

[midnightsadie]

don,t forget the bottom.make it air tight.

[agesilaus]

Foam insulating sheets, as thick as you can find, probably 4 or 6 inch with an electrical heating element inside if it gets really cold. Use multiple 2 inch sheets if you cannot find thick stuff. Do not use fiberglass insulation, it's worthless if it gets wet. Have a removable insulated lid to provide access to the tank.

I'd probably wrap the whole thing protective material like 3/8 painted outdoor plywood