If you have a male end of the locline, you could use a pvc connector you'll need to use a connector that's slip for the pvc and female end for loc-line. Assuming you have that.
If you have your heart set on Loc Line, reduce to 3/4" and then use a Y reducer (3/4" to 1/2")
http://www.bulkreefsupply.com/y-reducer-3-4-to-1-2-for-3-4-loc-line-modular-hose.html
Or save yourself the hassle and go with a 1" eductor.
http://www.bulkreefsupply.com/cpr-threaded-eductor.html
Unfortunately, the threaded venturi nozzles are 1 1/2", so wouldn't work in your application.
You might read this thread which discusses the same questions that you have.
http://www.reefcentral.com/forums/showthread.php?t=1631304
Ur better than my real mom lol
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