The thing is, before I replaced the tubing, I had the exact same setup, so I know the system can handle it...
EDIT: although now that I think about it I had the CPU first in line and not last, but in that case you would think I would see an increase in idle GPU temp...
So, I have been reading a lot of these forums while I have been putting together my first WC system.
The first revision went pretty well. I used vinyl tubing from HD and my CPU/GPU idled at 22 and 32 respectively. After a few days, the tubing sprung a leak (surprise), so I ordered 7/16"...