Return Pump Overkill

[ravechild]

I am in the process of upgrading to a drilled tank and I picked up a pump that I was planning to use as a return pump. It is a GX-8500 rated around 8500 L/h (approx. 2200 Gal/h) at 0-feet. Do you think this would be overkill to pump the water up about 4-5 feet with a 600 gal/h overflow in the tank??
I know I will have to add a valve to slow the flow but do you think that would be too much??

 

[squidd]

yep...

 

[ravechild]

I picked it up for next to nothing. Do you think it will still run if it is turned down that much. I was thinking of using a gate valve on the output side of the pump.

 

[hurt]

That is a large pump, if you only wish for 600 gph. But you could do a few things to make it work. First, on your return line, put a T in and then a ball valve off the T, going back into your return pump chamber.
Also, I would put in at least one scwd on the return line back into your DT. Another possibility to even further slow down your gph, would be to put two more scwd's off the original scwd. I have never done this, so it may not work, but I think it would. So you would have 3 scwd. I believe each scwd slows output by 20%. So you would have four return outputs into your DT, and lots of random flow.
Here's a diagram of the T with ball valve, the more you open this valve, the less flow goes into your DT, and vice-versa. Hope this helps.

 

[acrylic51]

What would be the purpose of sending it right back to the return chamber? Either go with a smaller pump or use it to feed something else as well

 

[funkyman]

I think if he split the return to the main tank (1100 / 1100), and after the head loss, elbows, blah blah, wouldn't it knock the gph down considerably? I think at that point he would be at the point where he could regulate the pump output, and / or divert some of the flow back into the sump. :thinking:

 

[funkyman]

Woops. Just saw where he only has one return. In the words of the immortal Gilda Radner:
........never minddd.

 

[hurt]

What would be the purpose of sending it right back to the return chamber?
Very simple. It slows down flow to your DT without making the pump-pump harder, thus it does not shorten the life of your pump, while not adding more heat to your tank, and it is a very easy way to adjust H2O flow. You can fine tune you gph very easily with this method. Also when you do water changes it makes it very easy. He specifically said he did want to try and use this pump. The more you H20 you send back to the same chamber, the less will go to your DT-depending upon how wide you open the ball valve-all, none, or somewhere inbetween- the ball valve makes it simple to determine how much flow you want.

 

[acrylic51]

Originally Posted by Hurt
Very simple. It slows down flow to your DT without making the pump-pump harder, thus it does not shorten the life of your pump, while not adding more heat to your tank, and it is a very easy way to adjust H2O flow. You can fine tune you gph very easily with this method. Also when you do water changes it makes it very easy. He specifically said he did want to try and use this pump. The more you H20 you send back to the same chamber, the less will go to your DT-depending upon how wide you open the ball valve-all, none, or somewhere inbetween- the ball valve makes it simple to determine how much flow you want.

So I guess what your saying that by putting a ball valve on any brand pump on the discharge side makes the pump work harder and shortens it's life??????

 

[hurt]

So I guess what your saying that by putting a ball valve on any brand pump on the discharge side makes the pump work harder and shortens it's life??????
Yep. The more friction/back pressure, the harder it is for the pump to turn. By putting a T in right above your return pump and off the T a ball valve, back into the same chamber--this will greatly decrease your back pressure and allow your return pump to operate at the full capacity always. As stated, it makes it very easy to control your gph back into your DT.

 

[acrylic51]

Boy!!!!!!!!!

Sounds like you should do your homework on throttling down pumps.....FYI throttling down a Sequence pump doesn't hurt the pump 1 bit and it actually makes the pump more efficient than running it wide open....If you don't believe me go th the other forum and and go into the Sequence forum and READ!!!! This information is directly from the manufacturer!!!!!!!!

Throttling down won't add any more heat to the water, and think that whole theory is out there....Again do some research and see!!!!!!!

 

[hurt]

Boy oh boy, you are obviously thee RIGHTEOUS ONE.

My fault, but the pump he is referring to is not a sequence pump, nor is the one I currently use. Hmmm, so how can you slow it down, without causing increased back pressure-what I had previously explained. He specifically asked how to slow down a GX-8500(not a Dart, Barracuda, or Hammerhead(reeflo), or any of the external sequences(Uno)). What did I do, help give an option to do what he asked for. What did you do, tell him to buy another pump? Hmmm, so you must obviously be implying that every pump out there is a sequence pump. So, can you throttle down any pump? Again, read his original post.

 

[ravechild]

Hurt
I appreciate your response. The pump is a magnetic drive, and I believe your suggestion may be the most effective one, because, at the same time it is slowing down the flow to the DT, it could be oxygenating the water in the sump. That is if I leave the end of the pipe slightly above the water line in my sump.

 

[nm reef]

Lets try not to get personal.....often leads to nothing but trouble and really serves no purpose.
For some pumps regulating them down via valves may not be a major problem....for others it can be. I believe I've heard the raves about sequence pumps....I run magdrives.....a 1200 and a 1800....both are slightly valved back and neither has caused any serious issues to date. The suggestion above could work very well....plus later if you have need for additional flow or maybe establish a refugium you have a means of doing so without additional pumps.

 

[golfish]

Originally Posted by acrylic51
So I guess what your saying that by putting a ball valve on any brand pump on the discharge side makes the pump work harder and shortens it's life??????

Originally Posted by Hurt
Yep. The more friction/back pressure, the harder it is for the pump to turn. By putting a T in right above your return pump and off the T a ball valve, back into the same chamber--this will greatly decrease your back pressure and allow your return pump to operate at the full capacity always. As stated, it makes it very easy to control your gph back into your DT.

What makes the GX differ from the Sequence, or Dolphin pumps? Isn't adding a ball valve just adding head pressure?

 

[hurt]

RaveChild-gald to hear it, I hope my responses helped you out.
Golfish-if you add a ball valve inline only then yes, it will add head presure and diminish the life of most pumps. What I was talking about was adding a ballvalve off a T above your return pump back into the same chamber. This will not add head presure. The more you open the ball valve the less water will go into your DT and the more water will be returned to your return pump chamber, the more you close the ball valve the more water will go into your DT. A very easy way to adjust the gph into your DT without making the pump-pump harder. This method will not add head presure to your pump....

 

[acrylic51]

Adding a ball valve on the discharge side of the pump won't hurt them pump........

 

[acrylic51]

Strangest thing I just thought of........ :notsure: I've been running the same Little Giant MDSC 4 for the past 8 years throttled back by a ball valve and it hasn't missed a beat

 

[hurt]

LOL, that's funny.

... He wants to restrict a 2200 gph pump down to just 600 gph. That roughly 3/4 of the pumps original purpose. Why would you want to make the pump-pump harder, when you can let it run full open and still decrease flow to your DT....

So you are trying to tell me that will not increase the back presure on the pump?

.
By the way your little giant is an external pump, the GX-8500 is an internal pump.

Even at that you are telling me your little giant is throttled back 3/4's.

You will increase the amount of heat the pump puts into the tank if you take 51's advice with an internal pump

Again, I hope I've helped you RaveChild, if not listen to 51.

 

[acrylic51]

There's the problem right there using a submersible pump......Why not just use multiple returns or better yet a manifold system and trust me you'd suck up the GPH that way and the pump put to better use.....