increased head?

i just bought a little giant pump with 18 ft of head to pump water to my new set up from my water change water container in the basement. im not sure if its enough to reach my tank or not. just wondering if i cut down the tubing half way up from 1/2 in to 1/4in tubing if it will increase the amount of head or not?

 

No, it won't. It will reduce flow. If it is just one floor down it's not 18ft.

 

+1 Will reduce flow and it's should not 18' unless you are going from a basement to second floor, or have a really big basement

 

Yes it will.
Head is resistance to flow and reducing the line size will definitely cause resistance. You want to increase the line size from 1/2" to 3/4" to reduce head not make it smaller so you have less resistance to flow.

 

Wouldn't this have diminishing returns though? You wouldn't be able to say, increase the pipe size from 1/2" to 2" to decrease head loss because the weight of the water would slow down the pump more than the decrease in resistance. Maybe there is a formula that combines the resistance of the pipe size and the head loss from the wieght of the water?

 

You are correct; there is a balance point. And yes, there are formulas, but that gets involved in a hurry as you'll need the friction factor for the end-wall effects, which is a function of pipe material, fluid, and flow.

 

I wonder if there is a quick calculator out there that would give a rough estimate. I could see how there would be many variables in the problem. But I'm no physisist (I can't even spell it right)

 

http://www.reefcentral.com/calc/hlc2.php

I think this should work

 

perfect thanks guys much apreciated

 

Nice link. That will be very helpfull. Thank you.