Fibreglass pool lifting - please help !!!!

[bobpants]

Help !

I just installed a fibreglass pool (about 5 feet deep). When the excavations were being

done, ground water started coming in at at about a depth of 4 feet. The pool was put on a

gravel base as per the makers instructions and backfilled with gravel also. Concrete is due

to be out round the rim in a few days

I also left a 4ft square & 4.5 ft deep 'pit' at one end for the pipework around the skimmer

etc. & put a pump in this pit as a safeguard. The pool is currently 3/4 full as there was a

leak around the skimmer which I had to fix.

The problem I have is it seems the 'pit' just keeps starting to fill with water and I

believe one corner of the pool by this pit has already lited 1 inch in a week. Am I right

please in thinking.....

i) The water weight in the pool would push the ground water out from underneath it into this

'pit' at the end?

ii) The 'pit' should only fill up to the ground level of the water i.e. only about a foot

above the pit floor? It seems to be going higher than this and I don't know why.

iii) If the water level in the pit stays below the pool water level, am I safe that it won't

lift any further?

Any help and advice gratefully received.

Thanks
Bob