Whatever goes on the lawn for a long time will kill the grass. It will recover when you remove the pool but I don't think you can protect it as such.

The only way to protect the grass is to move the pool every 2-3 days but it will depend on how big the pool is whether that is possible

Can you put the pool on a platform on stilts? If you get a 6-8 inch clearance the grass should be ok. If it is still suffering from lack of sun even with the stilts, then some carefully placed mirrors to redirect the light might help.

Trouble is, if its for children they probably wouldn't like to splash around and land on a hard surface. Its probably safer on the lawn.

Good point although the ground is very hard with all this sun, mine is like concrete!! Perhaps Alfie could place a padded quilt between the platform and the pool?

Funguy you are making daft suggestions again...

thank you all