Insulation Jacket for Coffin-shaped Water Tank

BarraOG

I have two 70 gallon water tanks, 64x24x19 inches. I cant find insulation jackets anywhere that are this size. Can I just buy a few jackets and cut them to size and stick the pieces together with gaffer tape? Are they just fiberglass inside a plastic bag?

whizbang

i would use rigid foam sheeting. Glue together to make a box, but spend the time to get the upper edge plane, so the top cover will sit tight without air leaks.

phormium

The best insulation I had for a tank was a couple of old duvets, my last tank was one of the uninsulated type so I packed the duvets all around it. When I had to change it I bought the insulated type and assumed it was going to be so much better than my diy duvet job but turns out the water used to stay hotter in the old tank than this ready insulated one!

TimHorton

I put 150mm insulation into black plastic bags and strapped it to the side with rope - No issues 4 years down the road.

BarraOG

I have a brunch of old fibreglass insulation so i might just put it in bin liners and tape it along the sides. Thanks!