[wickedfrags]

what size hole? the white hayward bulheads are best, that being said you should be able to get the leaking to stop regardless

using whatever gaskets the bulkhead supplier provided should work, consider using some "orange" teflon tape on the male threads. Another option is to use white thread sealant, pipe thread "Dope" on the threads. The same sealant used for natural gas lines, propane etc. It is not a permanent seal, you can still take the bulkhead apart.

you should be able to get the leaking to stop only hand tightening the bulkhead, but use no more than a half-three-quarter a turn after hand tight to avoid cracking the glass. Last option is to put silicone on the threads, but that is the least professional approach....and the last option! good luck