I found a large plastic water tank on a skip and want to use as a water butt. On the bottom of the tank are 2 holes, around about 25mm, have not measured properly yet. This must be where 2 pipes went through. Tried to cover with impact glue and some strips of thick plastic but failed miserably! Is there a plumbing connection i can use? Some sort of male/female connector to cap the holes? Would seem a shame to throw away. Thankyou in advance