Originally Posted by NaeKuh
the MAX head pressure in your system pump / 2 = max length in tubing one should use.
So a D5 = Maximum head 10 ft (3.1 m)
That means no more then 5 feet of tubing.. 7 feet if ur using really low restriction EQ.
Do not pass 10 feet.
If you need more then 10 feet, you need a second D5 so you can double the head pressure, from 10 -> 20.
Which would give you 10 feet of tubing to play with, and another 10 feet of restriction in eq blocks.
Based on Martin's numbers, 10 feet of 7/16" ID tubing incurs a pressure drop of about 1 psi at 2 GPM.... your rule of thumb has a crazy amount of pad in it.
The difference between 10 and 20 feet of tubing in a system with one CPU block, a low-restriction FC GPU block, triple 120mm radiator, and a D5 on setting 5 would be on the order of 0.1-0.2 GPM. In other words, not a significant enough impact on flowrate to matter above 1GPM.