sump problem

I bought a 120g. Its an upgrade from a 90 gallon.
I am having a some problem with connecting the return pump.
The sump is a 40gal breeder with a hole drilled on the left side. The previous owner drilled it, and i cant figure out how i can connect my pump. I generally like to connect flexiable tubing straight from the return pump to the bulkheads going up in the tank. Heres a pic of what i am working with.

http://img210.imageshack.us/img210/9789/20120121133915665.jpg
http://img607.imageshack.us/img607/6311/2012012321282478.jpg
http://img217.imageshack.us/img217/3246/2012012321291026.jpg

Just because the hole is there, i would have to connect the return pump with the bulkhead coming out of the sump. (first pic)
I went to my local hardware store and they said they dont have anything that will make the bulkhead in the sump small enough to connect the tube to. It would be so much easier if that bulkhead/hole wasnt there.

Any suggestion on what i can do?

 

Im assuming that was there for an external pump. are you wanting to have an internal pump in the sump?

 

I would just cap it off if you don't want to use it.

 

yes my plan is an internal pump.

More easier for me would be covering that hole but i am not sure whats the best way to do that. I was thinking about adding a ball valve on the outer side of the pvc thats connected to the bulkhead and just closing the valve it off. idk if that would cause any leaks?
Or i can add 2 valves just for a stronger hold.

 

A 42 cent pvc threaded plug/cap and some teflon tape and you're golden!

 

If its you're sump and the hole is high up, it shouldn't need much of a seal, as water shouldn't really be that high in your sump very often!

 

The hole is actually more towards the bottom. I am thinking about looking for an end cap and then adding a valve on the other side just in case.

 

the inside of the bulkhead is not threaded would a non threaded work as well?

 

As Illusions said, cap the bulkhead, using the outer threads in this case. Take the bulkhead off, if need be, and find the correct cap in your plumbing section of local store.

IMO, a ball valve isn't going to create the best, long lasting seal.

 

a piece of plexiglass and some silicone?