Ok,
So I have never used this product, so I am a little hesitent to recomend it, but my
LFS that i trust does recomend the use of this, so I may try it in teh future.
It's called the SCWD. You connect one end to you return line and the system, tees off to other lines. The unit automatically switches between the 2 lines, alternating the flow.
I am sure that you could figure out a way to plumb it to your
PVC.
SCWD Wavemaker - Switching Current Water Director (Squid) (Saltwater Aquarium Supplies > Wavemakers > External )
Sorry that I do not have personal experience this product, but as I said above, my
LFS does sell and recomend this product, and I do trust them.
Good Luck!
John
