Sunyakits,
Listen to Naekuh. You are just recirculating the heated up liquid between gpu1 and gpu 2. With a large temp delta between gpu1 and gpu2, you are prone to video crashes.
While you are at it, you are killing the head pressure, which is really ultimately what's important to cool your video cards. That parallel setup you have there does not work as well, and you are wasting the entire water cooling effort. If you really want a parallel setup, get two pumps and two radiators, with Y junctions coming off the reservoir.
You appear to be driven by looks rather than performance. Who cares about how it performs as long as it looks coll, right? The whole forum is headed that direction as well.
Number Three here. IT DOESN'T WORK