Leaking Filter

[Ickle]

I have a filter which is leaking from the under drain so i am currently emptying the filter of sand so as that i can get to the drain.
I am trying to work out what type of filter i have in my plant room, as noone seems to be able to name it for me, i havent got a picture of it but i shall describe it, if anyone has any ideas could they please reply.

Colour - Blue
Size - 30"
Type - Bobbin wound
the lid is about 6"
the under drain comes down from the middle bottom and out through the skirt.
if anyone wants to have a guess please feel free.

i have tried talking to Astral, Plastica, BTU, Certikin etc, but no joy as yet.
If you can please help me