Leaking from my main drain

[knightsy]

My overflow pool loses about 10 ton of water every 4 days so i have drained it and have taken the main drain cover off and i keep getting water coming out of the concrete round the plastic main drain into the empty pool, the bottom of the pool is well above the water table. If water comes out does that mean i will lose water from the pool when it is full? Should the concrete around the main drain be sealed? It seems the concrete around the drain has disintegrated and no longer encases the main drain. Can anyone offer any suggestions?

 

[gwegan]

Welcome to TFP.
. We need some overall pictures.

By main drain you mean a central drain in the bottom of the pool.

Was this how it looked when you Pulled the cover?

Is the drain line itself water tight?

Is the surrounding concrete solid or crumbly?

Can you see rebar?

Hoe large is that void?
K

 

[knightsy]

yes central drain
yes that was how it was when cover was removed
the drain line is water tight
solid but with lose on the bottom like bits of stone
can not see any rebar
100mm to lose stone