garden pond losing water

[RocW]

Some time ago we sank a plastic trug into the garden and filled it with water to make a very small pond. Although there were no signs of leakage, the water level reduces considerably at times, particularly when the weather is wet. Is this some form of osmosis and is there any way to stop it? We are having to top it up with anything up to 7 gallons in one day.

[Envii]

There can be several reasons why water levels drop but this is an in depth post about why ponds lose water, hope it helps! https://www.bio8.co.uk/blogs/665/why-is-your-pond-losing-water