how to make a water tank

this is amazing
https://www.facebook.com/reel/991481926542088

That is a pretty cool technique.
1. I wonder how they built the metal frame, or whether it is available to buy where they live?
2. I wonder if the wire ends up encased in the concrete? I would have thought they'd have had to add concrete to the inside after removing the hose.

Considering how difficult/expensive it is to get large water tanks on my island, a simple system to build a safe and reliable one would be really useful.

Are there different types of concrete that are safer for water storage?

Here is a more complere film of the same story  https://www.youtube.com/shorts/BLv2pHUs3q8

Good hunting John C! The second video, on youtube, gives a much better explanation. In fact, there's enough info that some of the engineering types I know could probably build such a thing and have it work as intended.

If materials were easier to come by, I expect in my area they would put a penetration for a tap, rather than having to use a bucket to get the water out.

Jay Angler wrote:If materials were easier to come by, I expect in my area they would put a penetration for a tap, rather than having to use a bucket to get the water out.

You could use a small amount of wooden framing to encase and support the tap, and then use the hose for the bulk of the structure.

Or you could exit from the bottom, with a short riser to get above the inevitable sediment layer. Then you're not disrupting the coil of tubing.