That's a huge pool, but can you fit a cover for it?  Covered pools supposedly can decrease evaporation by up to 95%.  Of course this depends on how often you actually use the pool vs keep it covered.

On 2/27/2021 at 8:00 AM, Crossy said:

I don't measure ours, just top it up when it seems low.

 

You could try the bucket test.

• Get a bucket and put a mark about 1" down from the top.
• Fill it with pool water to the mark.
• Mark your pool level.
• Leave the bucket by the pool for 24 hours.
• If bucket and pool have lost the same amount, you have no problem.

 

I did the same test about 2 years ago.

For a better comparison, I recommend placing the nearly full bucket of pool water at least 3/4 of its height in the pool (on pool steps, for example) so that the water in the bucket always has the same temperature as the water in the pool.
The bucket should really be almost full, so that the wind for evaporation reaches the surface in the bucket water as well as in the pool surface.

During this test, of course, you should not make waves in the pool / swim  ;-)

 

 

I have one of these fitted to my pool....very inexpensive and low tech and seems to to a good job