CL question

[labragg1]

Ok, this may be a dumb question, but if I remember right--a closed loop does not have any head pressure--correct???

I am still trying to decide on a good pump for my CL, but I get lost in all the ratings and stuff on these pumps.

I'm stuck between a Dart and an Ampmaster 3000. I was going to buy a bigger pump, but am concerned about the noise and wattage consumption.

So between the Dart and Amp3000--what do you think.

Some say the Darts are not as strong--but they are pressure rated--I think.
The amp3000 uses less wattage and is supposed to be as quiet--but it's not pressure rated.

Someone help!!!!
:eek2:

 

[labragg1]

Oh--and I will be running an OM-4 way.

 

[fishy-doc]

i think it does not matter if there is head pressure on a CL or not, because it is just re-circulating the tank water right?

 

[OnTheReef]

If you are drawing water above the level of the tank water in your closed loop, then head pressure matters! Also, since a closed loop usually includes a distribution manifold of some kind, you will lose pressure and put some load on the pump as a result.

 

[wetWolger]

you wont really have any head pressure. But there will be loss of flow due to friction. Friction of the water moving in the pipes, but mostly increased friction at 90 elbows and stuff like that. My mag 12 for my closed loop probbably looses about 200 to 300gph due to friction. You can use the flow calculator on this site to get a semi-accurate number to how much flow you will be getting when friction is accounted for.

 

[labragg1]

thanks guys. that helps.