ID OD Pump question

[HippieSmell]

I have a Panworld 100px-x pump rated for 1270 gph at 4 feet of head. The outlet is a 1" OD and 3/4" ID. Since the inner diameter is 3/4", shouldn't 3/4" pvc be as big as I need for the pump to operate at full potential?

[bubareefer]

What you need to do to run your pump at its full potentail is convert the outlet and inlet to 1 1/2" pvc. That is were you will get your full 1270 GPH. If you use 3/4" or 1" pvc you will lose some GPH do to friction and back pressure.

[HippieSmell]

Why an 1 1/2"?

[bubareefer]

It is just how the pump is designed. I have talked to Panworld/Blueline direct about this subject. Part of it is 3/4" and 1" can only handle so much flow. It is like trying to suck a golf ball though a garden hose. It can be done but there is an easier way to do it.
The other part is more area inside the pipe the less the pump is going to have to work. Less work means less heat. Less heat means the pump is running easier and will flow better.
One more point to be made is using 1" or 3/4" pvc will add to you head height for the pump. go to: http://www.reefcentral.com/calc/hlc2.php
enter the parts you got now with 3/4" then, 1" and then 1 1/2" and see the results and see what happens. Or try it out with 1 1/2" that is what I run on my blueline 55 HD and the 40 HD that I have. Blueline is the same company as Panworld incase you didn't know that.

[HippieSmell]

Thanks, I wish I had seen that calculator before I did all my plumbing.