How to extend the life of a leaking ibc?

My greenhouse has a buried 1000 litre Intermediate Bulk Container (ibc)... only it leaks.... but it's buried, with hundreds of kilos of soil and a greenhouse built on top of it! Any ideas how I could line it to still hold water?

If not- I'll be filling it with gravel for thermal mass!

Can you use a pond liner to keep it from leaking?

With a greenhouse built on top of it how would get to it?

The ibc 'entrance' is a 12 inch round hole- this is accessible from inside the greenhouse. That is the only access without digging!

where is the leak do you know? you can "weld" leaks in IBC's with a soldering iron if it is somewhere you can reach with a soldering iron on a stick. Any form of silicon sealant would work as well but again that depends on where the leak is, straight down might work but on the sides would be hard. if it's in the side then yes a large pondliner balloon sounds good.

I don't know where the leak is- I assume 'the tap' which is at the bottom, even though it was closed AND had a threaded fitting on the outside in an effort to prevent leaks! Al of the water leaks out, so the tap seems to most likely culprit.

I'm not sure if these work without access to the drain hardware but it might do the trick:

IBC liner

Do you use the water for any other purpose than holding heat?
If not you may get away with using something that will flow through the leak and block it.
Bentonite clay may be a good one.
There may be commercial products as well.

What do they add to radiators?
Just kidding!
Some kind of spray like flexseal might work,  but I'm thinking a hydraulic cement or surface bonding cement might do.
Rapid Set makes a waterproofing cement that might work.
If you could reach it an entire tube of pure silicon caulk might plug the hole.
Even an expanding  clean out plug made of rubber, could work,  if your reach is long enough.

Skandi Rogers wrote:where is the leak do you know? you can "weld" leaks in IBC's with a soldering iron if it is somewhere you can reach with a soldering iron on a stick. Any form of silicon sealant would work as well but again that depends on where the leak is, straight down might work but on the sides would be hard. if it's in the side then yes a large pondliner balloon sounds good.

Please be careful with fumes when doing plastic-welding!

Thermoplastics, or plastics that melt when heated, can indeed be welded: it's a welding process because the materials are actually melted and flowed together. Done properly, it is a strong fix. You must identify the plastic properly (not too hard for something like an ibc) and use welding rod made of that same material.

But safety is important for this process, because heating plastic to that point also releases fumes. I found this out the hard way last year while repairing some plastic items. The lung doctor said it's a known phenomenon and provokes a particular kind of asthma. By God's grace I recovered pretty much completely, but for a few weeks I was very scared. It felt like I was always out of breath.