Help with pump set up

[ravenjred]

Hi,
I finally got my tank set up and the return pump seems to be returning water in pulses rather than a steady flow. When I plug it in it drains the return section of the sump so that it is sucking air and then when I add more water to the return section it fills the tank to the point of it overflowing. Any help would be greatly appreciated. Thanks.

 

[redfishbluefish]

It sounds like your pump rate of return far exceeds the rate on your overflow. What pump do you have; what size is the DT; and what overflow do you have?

 

[NanaReefer]

Yes. Over flows are rated by GPH. If your pump is rated much higher than your over flow, your tank will not drain fast enough to keep up.
My over flow is rated for 700gph, my return pump has a max gph of 565gph. However with head loss I'm getting about 465gph on the return.

 

[ravenjred]

I'm not sure what my overflow is rated. It is a Marineland 60 gallon cube with a stock overflow and return. Both bulkheads take 1" PVC.

 

[NanaReefer]

What size is your return pump. All this info is important so that we can help.

 

[Reefing Madness]

If the pump is adjustable, slow the flow rate so that your overflow is waiting on the return water to fill.
Or T off your return pump, add a ball vavle onto it, and fine tune the return rate of flow from that stand point, making sure that the overflow is waiting on water from the return.

 

[ravenjred]

The return pump is a Water Blaster HY-5000 and is rated at 1450gph at 11 feet.

 

[redfishbluefish]

A "conventional" overflow with a 1 inch drain should easily handle 700 gph.


As Madness pointed out, if a newer DC pump, they are controllable and you could easily dial it back to a reasonable flow rate. If not controlable, again like Madness stated, tee off the return line with a valve. This line returns to the sump. You do not want to put a valve directly on the return line...this will shorten the life of the pump. Here's an example of what we are talking about. What you don't see in the picture is the valve all the way over on the right.

 

[redfishbluefish]

The return pump is a Water Blaster HY-5000 and is rated at 1450gph at 11 feet.

Here's a rough headloss graph of the Water Blaster:

 

[racin2438]

You'll likely need to add a ball valve, or a union ball valve to be able to control the flow. Your pump looks like it may be a bit larger than you may need.

What size is the overflow box?

 

[AZDesertRat]

Plumb a ball valve in the return line and adjust it down until the flushing action quits.
Do you have any photos of your overflow and standpipe plumbing? Any restriction at all in the gravity overflow can cut flows considerably. I use a HY-5000 on my 100G with a single 1" overflow and the overflow barely keeps up with the retuen pump with the valve fully open. The 5000 is probably too much pump for your application depending on the size of your sump and return section. My sump is a 30G and the return section holds about 6 gallons so can drain quickly if the overflow is not keeping up.

Contrary to popular belief, placing a valve directly in the return is far better than placing a tee in the line and returning flow to the sump. When you return flow to the sump the pump actually works harder and does not last as long, you use more not less energy, ceate more heat and more noise. When you study Bernoulli's theory and The Laws of Affinity this becomes more clear but what it comes down to is centrifugal pumps only draw the power necessary to do the work required of them and when you add head less work is required. When you return flow you are making the pump work harder to pump the water you are returning to the sump. A simple test with a Kill A Watt meter proves this to be true. It doesn't make sense but its the truth.

 

[ravenjred]

Here is a pic of the sump. The ball valve is in the return line. The overflow is the standard for the Mainland 60G. cube. It has a straight piece of pvc on the drain with a U shaped elbow on top. The water is up to the level of the side hole in the drain.