# Planning on converting to sump filtration - help choosing a pump



## Bunny (Oct 13, 2013)

Hi everyone, 
I'm in the process of upgrading from a 30 gallon to a 100-120 gallon tank (custom build, unsure of final tank height). The plan right now is to convert the current tank to the sump and I've found a decent guide on DIY sumps. I am utterly lost however when it comes to choosing a pump.

Can anyone help me on this matter?

If it makes a difference the guide I'm using to figure this out is: Build Your Own Custom Sump Filter and I'm following the design for "Standard Freshwater Sump".

The tank I'll have is a used one I'm planning on tearing down and replacing the cracked side panel, Currently the bottom is drilled and I'm thinking of switching this to be the back panel on the rebuild depending on hole location/scratches, etc.

Does the hole location make much of a difference to pump power needed?

Are there other parameters to consider when choosing a pump?


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## target (Apr 21, 2010)

When choosing a return pump you need to consider 'head', that is the amount of height the water will need to be lifted to by the pump. For example, say your stand is 30" high, and your hole in the back of the tank is 18" from the bottom of the tank, your head for that set up is 4'. This is simplified as any elbows your piping has will add to your head. You'll need to determine what amount of head you are working with and find a pump that provides the right amount of gph (gallons per hour) at that head. 

As for hole location, bear in mind that unless you put a check valve on your water return lines, your tank will drain everything above the return holes back into your sump. Also, how are you planning to get the water down into the sump? The same issue occurs. If the power goes out, the main tank will back siphon everything into the sump to the level of the holes. So if you have the holes near the bottom of the tank it will drain all of it and most likely flood your sump. Holes should be nearer the top IMO.


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## Bunny (Oct 13, 2013)

I understand about the pressure-head, how do the elbows add to the effective head height? is it just their length that adds to it or is it more complicated than that?

What is the recommended gph for a ~120 gallon tank? Is it the same idea as a standard filter in that it should be about 2-3x the total volume per hour cycling through?

Would the check valve on the water return lines be ideally in the line itself or part of the valve where it connects to the tank? (these are typically called bulkheads right?)


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## target (Apr 21, 2010)

Elbows add to the head by creating an area with higher friction, the water has to change direction. here's a sheet that shows the friction loss of fittings: PVC - Equivalent Length Friction Loss in Fittings

I would think the gph would be the same as with a standard filter. Decide what the turnover rate you want is and go from there.

In my set up I have the check valve right almost connected to the pump. That way there is no plumbing below it to drain back into the sump. If you had the valve right near the bulkhead (which is the piece going through the hole in the tank), you would still drain the lines back into the sump. Which if you don't overfill your sump should be ok. Are you planning 1 return line? I have mine split for 2 returns.


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## Bunny (Oct 13, 2013)

I'm honestly not too sure what the plan is, I looked up the BeanAnimal design with the weir/overflow and 3 standpipes and it seems like a good idea so I'll probably follow that. As for return lines... I never even considered that. Is two better? What are the advantages and disadvantages?

Thank you so much for your help. I'm starting to feel a little less lost with regards to all of this - my only experience is with a 30gal tank with a HOB filter


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## jbyoung00008 (May 16, 2011)

Benefit of 2 returns is better water circulation. Some people will even split the 2 returns at the tank to have 4 returns 

Im going to be building a sump in the near future. Good luck with yours and keep asking questions. I have a lot to learn as well


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## Bunny (Oct 13, 2013)

Thank you  I think I'll start a thread in the DIY section about this as its not technically 'equip talk' anymore


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## target (Apr 21, 2010)

My 90g tank is my first experience with a sump, a bean animal overflow, and plumbing to the extent that I did for the build. I like the dual return because it spreads the flow around the tank. Take a look at my thread for the plumbing I did. I am quite pleased with how it turned out.


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## shift (Dec 21, 2012)

I just have an all in one tank w/sump and it has the returns at either end which is a great way to do it.


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## The Guy (Nov 26, 2010)

I just have the one return to the tank over the rim and in on the left side. Kind of wished now I had run two returns, one on each end over the rim. I suppose I could tee it to the right hand side if I added a couple of ball valves to even out the flow, what do you guys think?


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## The Guy (Nov 26, 2010)

Sorry Bunny didn't mean to hijack your thread, kinda got caught up in the return piping comments, opps!


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