Advice on Water Tank

[Margrave]

Hello,

not sure this is the right forum, but here it goes: I have a 3,000 litre fiber(glass?) water tank, with its metal valves and the like as you can see in the attached images. It was used formerly by a neighbouring winery. It is full to the top with rain water and set inside a wooden shed that protects it well from sun and winds.

Here in my region it is a bit difficult to collect that much water because of rain issues. But, winter is coming. Temperatures here usually stay a couple of degrees below zero Celsius, in average most of the time from -2C to +2C (26F, 29F). Problem is every five or four years there can be lower temperatures, the record I registered a couple of years ago was -10C (14F) and this lasted for one days only. The temperature went back to -3C soon after.

Due to the lack of rain issue I would feel bad throwing away all the water in the tank now just to not have it back when spring comes and perhaps not much rain with it. My legumes and strawberries will suffer without watering them in summer with rain water collected in the spring.

I was thinking of draining the tank only for it to hold half of its capacity (1,500 litres) and perhaps with this avoid the frozen water to burst the tank just in case there temperatures go less than -5C for several days. But I am not sure this will be safe/work. The tank is made probably of fiberglass. It may have some elasticity, but I am not sure. There is also the problem with the metal valves as you see in the images.

Is there any way to protect the tank, valves to they will not suffer in case of short lived cold waves?

Any advice is welcome!

Water Tank Images
https://diigo.com/0ahh7i
https://diigo.com/0ahh8g
https://diigo.com/0ahh8l

 

[TripleSix]

Any electric to the shed?
Insulate and heat it.

Fit trace heating to the pipework.

Or wrap the valves in insulation, you could stack all around the tank with straw bales as a cheap form of insulation.

 

[fastfish]

Not so cheap anymore

 

[Barleycorn]

Chuck some empty five gallon cans to float on top. They will take the strain of the ice and protect the tank.

 

[Davey]

I'm not sure you will get much more than an inch of ice on the top so, as long as there is a gap at the top you will be fine.

We have an icb in an open faced barn which is plumbed up to the mains (due to poor water pressure and freezing pipes in winter) and never had a problem. Plus we have ibc's out in the fields where there's no mains water and even left exposed we've only had issues around the outlet at the bottom which a bit of straw sorts no problem.