Is my return pump going to be too powerful?
- Thread starter Harris3005
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You can use this tool http://www.calctool.org/CALC/eng/civil/hazen-williams_g to approximate the amount of flow that your drain will achieve under full siphon and then plan the pump accordingly. Whether your pump is approximately correct or not depends on the head pressure for the pump and the drop for the drain.
Bruce
Bruce
Or this tool if you find it easier. http://www.beananimal.com/articles/hydraulics-for-the-aquarist.aspx
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Harris3005
Active Member
Thanks very much for these. Here are the results I get, I think I've entered the correct info although it doesn't take into consideration my 90° turn into the sump.
If that's correct it's says I'll be getting around 2,400 gallons per hour through the 1 inch drain? Can that be correct??
Fishfinder
2500 Club Member
You can't have a drop that's longer than the pipe length
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Harris3005
Active Member
Good point, I've put the figures in the wrong places! I'm really not doing very well here[emoji23][emoji23]
Thanks very much for these. Here are the results I get, I think I've entered the correct info although it doesn't take into consideration my 90° turn into the sump.
If that's correct it's says I'll be getting around 2,400 gallons per hour through the 1 inch drain? Can that be correct??
Sure about the drop vs. length? I'd guess you are in the range of 1600-1800 gph with your elbow so if you consider that your pump has at least the same 36" head, I'd say it is ok to underpowered rather than overpowered for this tank.
Bruce
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Harris3005
Active Member
Just got the measuring tape out and checked the pipe length properly and you were correct to question my drop v length number! The pipe length was a lot longer than I thought when I included the vertical pipe after the 90°. With the 51" pipe length entered properly I'm getting 1920 gph. Does that seem more realistic?
Here's the drain pipes from underneath:
the elbows will reduce flow somewhat which is why I guesstimated 1600-1800 gph considering that you calculated around 1900. Now just determine how much flow your pump will have at the height where water enters the aquarium and you will know. I have become a big fan of oversizing the pump and flowing into a manifold that handles all of my reactors as well as the return. In my 75g that is being rebuilt, I am going to put the skimmer (Lifereef venturi) on the manifold as well to get all of the extraneous pumps out of the relatively small sump.
Bruce
Bruce
Shaun Sweeney
Active Member
One issue that hasn't been mentioned here is noise level. I'd put gate valves on both drains and be prepared to use either as the main "full syphon" drain. I don't think the pump size is going to be a problem because as already mentioned, you can always valve the return. You could also consider getting a bit fancier with the outlet of the return in the tank. Diversify it a bit and have two or even three adjustable nozzles that you can move from time to time.
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Harris3005
Active Member
I think once I'm more confidant with it all I'd like to have it set up that way but my sump is pretty big (50") so, at least for now, space in there isn't an issue for me.
Going by this chart for my return pump I think it will be almost perfect for the flow you've helped me work out? Mine is the 9000 model.
Thanks for all your help with this Bruce, I really appreciate it!
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Harris3005
Active Member
I'm hoping that if I can get a herbie like set up using either of the holes I should get it pretty quiet?
I really like the idea of the nozzles on the outlet for a more varied flow. I'm going to try and work out how I could do this now!
Thanks.
donnievaz
Well-Known Member
I'm going to be setting up a 92 corner, 3/4" return, 1" drain, with a ~20 gal sump. I recently did a test run using a Jebao DCT8000. I cranked it all the way up and the drain handles the flow with no issues. I won't be running it that high but wanted to see what would happen. Unless I'm missing something you'll be fine.
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Harris3005
Active Member
That's good to know, thanks very much mate!
Yes, it looks like the pump at max output is fairly close to the calculated flow. You should have no trouble at all. Good luck!I think once I'm more confidant with it all I'd like to have it set up that way but my sump is pretty big (50") so, at least for now, space in there isn't an issue for me.
Going by this chart for my return pump I think it will be almost perfect for the flow you've helped me work out? Mine is the 9000 model.
Thanks for all your help with this Bruce, I really appreciate it!
My sump is small because it is a 75g corner tank and the space is very tight. It previously had a 2 x Mag 9.5, one for the return and one for the skimmer, as well as a powerhead running the GFO reactor. This like running the tank with a 200W heater on all the time so it needed a chiller to keep the temp below 82. I am going to rebuild with a Fluval SP6 and have it drive the return, skimmer and reactors and see whether I can live without the chiller (it is an LED only tank).
Bruce
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Harris3005
Active Member
That's a cool looking set up. Looks really slick. Will you have to sit the tank slightly out from the corner due to the sump position?
donnievaz
Well-Known Member
That's just a temporary stand for testing. I'll be doing a full oversized built-in in the house that will accommodate the sump. So yes it will be somewhat out from the corner but not too much.
When I first started reefing a lot of people told me that a 1 inch drain would only handle 650 to 700 GPH. I also saw that number posted on a lot of the forums. I don't know what nudnik decided to be cute and throw those stupid numbers around but they are totally false and a plague to this hobby. I have a single one inch drain and a 1 inch emergency drain, my ecotech l1 has 1 45° bend going up 2ft directly into my return. The single one inch drain pipe handles it with no problem and that's with multiple 90° bends.
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