My Leak Problem. Help!

[osmosis]

Here is my basic pool info.:

Size: About 8X4 metres
Age: 4 years old
Filter: Sand
Cleaner: Baracuda G4
Chlorinator: Zodiac Clearwater
Current pool temp: +/- 24-28 degrees C.
Ambient temp. over the last two months: +/- 29-30 degrees C.

I noticed about 2 months ago that I have been having to fill the pool every week and I am losing about 8cm of water a week. I did the bucket test which showed a substantial difference in water loss (more from pool).

I called the builder who dived in, said that it was a leak from the hydrostatic valve. He replaced this but the water loss continued.

I engaged a leak detector who couldn't find anything.

Where do you think I should go to from here. Any suggestions welcomed. Unfortunately we are under water restrictions at the moment, so filling may be prohibited soon.

Many thanks.

[dynamictiger]

First step is repeat the bucket test.

This time though test once for 24 hours with the filter system running continuously and then 24 hours without.

This test will show if the plant or pool is leaking.

If it is definitely the pool using phenol red slowly squirt a little around your pool light and most likely around your skimmer connections and see if it tracks.