need some help with a leak

[Doug]

Is it in an overflow? If so, then it can be drained and a seal put around the bulkhead. If not, then I guess the only option is to try seal the outside of it.

Although not much help to you know, this is why I always put a bead on the outside of the bulhead before attaching and then bead around the inside, protecting the rubber seal.

[fmelindy]

unfortunately my standpipe in this situation is out free in the centre of the tank.... No overflow chambers here....

and yeah, that immediately occurred to me as something that would've been a good idea but unfortunately not until after this already happened.