Pump slower using nylon tubing

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FishStarter89

Aquarium Advice Regular
Joined
Jan 28, 2009
Messages
82
Location
Carrollton, GA
About a year ago, when I started my system, I received ample criticism for using 1.5" PVC on my return pump. Many experienced hobbyists told me that using the wider pipe would increase head pressure and actually lower the GPH of my return pump, thus 1" was preferable. I was also advised that using flexible nylon tubing was preferred to PVC because it reduces sound and also head pressure. Having a little extra time on my hands this weekend, I upgraded my system taking these considerations to mind. I replaced my PVC return using 1" braided nylon tubing.

My return seems to be running much slower as the water line in my sump is higher (with the same amount of water) and I had to turn the ball valve in my overflow to keep it from gurgling. The pressure on the loc-line return feels lighter and I think my pump is actually louder now. Does anybody have any idea what's going on?
 
2 things come to mind.

Leak at the connection of the hose to the pump.
Or
By adding hose you've increased the length the water has to flow.

Closest route is always a straight line and having a curvy hose is adding more distance.
 
Sounds like a great case of if it ain't broke, don't fix it. I'm in some agreement with fatboy here, but without any additional information it is hard to make any real conclusions. We're trying to roughly calculate elbow angles and length we aren't aware of compared to the still unknown length and sag of flex tubing.
 
What kind of pump is it and how is it connected to the return line?
 
Leak at the connection of the hose to the pump.
Or
By adding hose you've increased the length the water has to flow.

I've ruled out a leak. Not impossible that the length of the hose might have something to do with it but the hose is actually a few inches shorter than the PVC.

What kind of pump is it and how is it connected to the return line?

Mag 9.5. It's connected through pvc fittings including a union which converts into the nylon using a barb fitting.

Update: the noise is no longer an issue. I was able to move some things around and it's quieter than the previous setup. Still no progress on the lack of capacity.
 
Is there a way to connect the braided tube directly to the pump and use a plastic clamp to keep it snug?

Correct me if I'm wrong, but the tip of the barbed piece could be a lot narrower than the inside diameter of the tubing, and could be a reducer in itself... Just thinkin out loud.
 
The narrower tip of barbed piece is a bottle neck and it has a similar effect of a valve not fully open. If you reduced your return pipe you also reduced the rate of flow. What you heard and believe in is the opposite.
 
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