Leaking water tanks Beneteau

[oceanis400]

I have a Oceanis 400 with fibreglass tanks in the hull.The fwd tank appears to have a small leak somewhere.I have removed the bunk and all woodwork but as expected the tank sits in part of the hull grid liner and it is impossible to inspect.Has anyone experienced a similar problem?.Will I need to cut out the whole top of the tank? Has anyone else experienced this problem on a Beneteau?
Thankyou for any suggestions

[infonote]

I know someone who had a similar problem.

Try removing the watertank and add fibreglass under the water tank. This will prevent the water from leaking.