# What size pump for a wet/dry?



## Guams (Aug 21, 2009)

I'm in the building stages of a wet/dry filter, and one of the last parts I need to figure out is... what size water pump will I need?

Here's what I've got so far:

Display tank = 55 gallon (standard footprint)
Wet/Dry = 30 gallon

I'm using a skimmerless overflow design from the library, therefore the water from the display tank will flow, via siphon, into the overflow. From the overflow, it will drain (by gravity) through 1" PVC into the wet/dry. Once in the wet/dry, the water will flow into drawer #1 of a Sterilite set-up. This first drawer will house the mechanical filtration (poly-fil and another more porous material) and will be drained by a series of holes drilled into the bottom of the drawer. It will then make it's way into drawer #2 which will have the bio-filtration (pot scrubbers). In the second drawer, I cut out most of the bottom and the pot scrubbers are resting a piece of eggcrate for drainage.

From drawer #2, the water flows into the 30 gallon tank, where it will be heated and pumped back into the display tank. And because of the size, it may or may not become a plant refugium in the future.

I've read that 1" ID PVC will drain anywhere in the neighborhood of 300-600GPH. But according to FlexPVC's (http://flexpvc.com/WaterFlowBasedOnPipeSize.shtml) charts, 1" PVC will drain 960GPH when gravity fed.

So... my question for you folks is: What's the correct flow-rate for 1" PVC? *AND* What size should my water pump be?

Here's a quick drawing of my plans... sorry it was done is MS Paint.  I didn't want to take the time to draw it in Google Sketch-up.


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## Neogenesis (Jan 4, 2008)

I'm using 1" vinyl tubing into my wet/dry, am using a ViaAqua 2300 and it does a fine job. When it does finally bite the dust I plan to buy a higher quality pump, but it provides good flow for now.

Scott


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## redblufffishguy (Jul 16, 2009)

With no friction loss, 1" PVC can handle 16 GPM, or 960 GPH. however, with a minumal amount of loss, you could easittly get 20-23 GPM (1200-1380 GPH) through the pipe.

It appears that you are olny asking the pump to lift the water a few feet, so you really don't have much head to worry about.

If it were me, I would use a 800-1200 GPH pump. you do have enough lift that some of the flow will be lost, and you can always add a valve in the return to limit the flow a bit.


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## Guams (Aug 21, 2009)

redblufffishguy said:


> With no friction loss, 1" PVC can handle 16 GPM, or 960 GPH. however, with a minumal amount of loss, you could easittly get 20-23 GPM (1200-1380 GPH) through the pipe.
> 
> It appears that you are olny asking the pump to lift the water a few feet, so you really don't have much head to worry about.
> 
> If it were me, I would use a 800-1200 GPH pump. you do have enough lift that some of the flow will be lost, and you can always add a valve in the return to limit the flow a bit.


That's correct, all I need for the pump to do is lift the water from wet/dry back into the main tank. I forgot to mention in my OP that the head height will be between 3 and 4 feet.

So, using 800-1200GPH, I won't have to worry about running the pump dry at all?


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## redblufffishguy (Jul 16, 2009)

That is why I suggested a valve on the return after the pump. You can partially close it to allow less flow to return to the tank. With a little trial and error, you can get it dialed to the point where you have exactly the same amount to water leaving the tank as entering it.

Partially restricting the flow should not harm the pump at all, but if you are worried, add a Tee in the return and put the valve on the tee. The extra water can be directed through the tee and right back into the sump. Using the tee will allow the pump to run at open flow without pumping the total volume of water directly to the tank.

Another option is to use a larger pipe size coming out of your tank. 1-1/4" PVC for example will allow for 25 GPM (1500 GPH) gravity flow. So if you use it, you will effectivly have more coming out than going in. The only problem there is that you can get too much coming out and loose your siphon, or overflow your sump. That method works best when the tank is drilled. In the case of a drilled tank, there is no need for the valve on the return line. You simply pump the water in, and once it reaches the level of the drilled overflow (granted it must be able to accomodate the flow) the water will pour out. The beauty of the drilled over flow is that you will ALWAYS have the same amount of water leaving the tanks as is being pumped into the tank, and by default, the sump will not go dry.


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## mithesaint (Oct 31, 2006)

redblufffishguy said:


> With no friction loss, 1" PVC can handle 16 GPM, or 960 GPH. however, with a minumal amount of loss, you could easittly get 20-23 GPM (1200-1380 GPH) through the pipe.


Wait...what? I may have misread that...but are you saying that the water flows faster WITH friction loss than WITHOUT? I'm no expert on fluid dynamics, but that sounds backwards. Please clarify/explain please.

To the OP, I've always used 600 gph as my rough estimate for 1" PVC, right or wrong. That's for a DIY overflow too, not a skimmer box. Not sure if that makes any difference or not. Anyway, I don't have my sump anymore, but when I did, I used two 1" DIY PVC overflows paired with a Quiet One 4000 pump. My pump wouldn't pump anywhere near what the PVC would flow, but that was fine with me. I wanted to make sure my overflow capacity was redundant in case something stupid happened like a dead fish or other debris blocking/slowing the overflow to the point that the sump runs dry or the tank literally overflows.

For me, I probably would have been fine with a QO 4000 at 5 ft head with a single PVC overflow, but adding the second overflow made it idiot proof. I'm a talented idiot, after all. :lol:

Good luck!


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## redblufffishguy (Jul 16, 2009)

when you add pressure to the water flow, the GPM increases. However, with the incresased flow, you gain friction loss.

Pressure flow and gravity flow work a bit differently. The pump will be pushing the water under pressure, and the overflow with be gravity. That is why i mentioned the two different flow rates.


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## Guams (Aug 21, 2009)

mithesaint said:


> To the OP, I've always used 600 gph as my rough estimate for 1" PVC, right or wrong. That's for a DIY overflow too, not a skimmer box. Not sure if that makes any difference or not. Anyway, I don't have my sump anymore, but when I did, I used two 1" DIY PVC overflows paired with a Quiet One 4000 pump. My pump wouldn't pump anywhere near what the PVC would flow, but that was fine with me.


I suppose this is what's confusing me. How do I make sure I don't A) overflow my sump and B) overflow my tank?

My assumption is that with the skimmerless overflow, water will stop moving between the tank and overflow when the water levels equalize (standard siphon behavior), thus preventing me from flooding the sump. But a gut feeling is telling me that I'm incorrect because of the water pressure when pulling the water from the bottom of a 55 gallon tank. Maybe I'm just over-evaluating it. :-?

So let's see if I can get this correct. From the tank to the sump, I should expect anywhere in the neighborhood of 600-950GPH and from the sump back to the tank, I should have a pump rated higher than the input? Should the return volume be too much, I just divert some water back into the sump?

Oye, it seems that when I take stuff out of my head and put it on paper it gets much more confusing.


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## redblufffishguy (Jul 16, 2009)

You have it exactly. Chage the volume diverted back into the tank intil the tank output matches the flow into the tank! You can check by monitoring the level of water in the sump (or the tank). once it stays constant, you are were you need to be


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## KaiserSousay (Nov 2, 2008)

A Big :thumb: :thumb: 
On a way to redirect any excess flow back to the sump, as well as getting a pump that is a bit more than you think you need. 
Most of the time, price differences between flow amounts, are only a few dollars for the higher flow pump. Money well spent. 
Most people use a PVC ball valve for their sump projects, I would suggest the use of a gate valve instead. The ease of making fine adjustments without the frustration of trying to move the ball valve a little this way and that. A little more money, but again, money well spent.


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## Guams (Aug 21, 2009)

Who would have thought it's so friggin' hard to find a 900-1000GPH pump in stores. I've called several places and nobody has anything in stock. I've got today, tomorrow, and most of Saturday off and I'd let to get moving on this thing. :x

Eh... I've got a couple other places to call, but they don't open for a little while yet.

/end rant


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## redblufffishguy (Jul 16, 2009)

Did you look here:

http://www.jehmco.com/html/water_pumps_ ... heads.html

their prices are great and they have a huge selection.


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## mithesaint (Oct 31, 2006)

redblufffishguy said:


> when you add pressure to the water flow, the GPM increases. However, with the incresased flow, you gain friction loss.
> 
> Pressure flow and gravity flow work a bit differently. The pump will be pushing the water under pressure, and the overflow with be gravity. That is why i mentioned the two different flow rates.


OOhhhh....I thought you were only referring to the overflow rates. Didn't realize that you were talking about pressurized return lines. Thanks.


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## mithesaint (Oct 31, 2006)

Guams said:


> mithesaint said:
> 
> 
> > To the OP, I've always used 600 gph as my rough estimate for 1" PVC, right or wrong. That's for a DIY overflow too, not a skimmer box. Not sure if that makes any difference or not. Anyway, I don't have my sump anymore, but when I did, I used two 1" DIY PVC overflows paired with a Quiet One 4000 pump. My pump wouldn't pump anywhere near what the PVC would flow, but that was fine with me.
> ...


There are two ways to handle this issue, neither is right or wrong. To each their own. It's impossible to perfectly match a pump and overflows without adding valves, etc so either the pump or the overflow will move more water.

I prefer to have my overflows move more water, so I had two overflows and a smaller pump. To me, that decreases the possibility of overflowing my tank due to a overflow malfunction. If one overflow gets plugged or loses siphon, I still have the other to prevent my tank from overflowing. It saves me money on the initial pump purchase, and saves me money on electricity down the road.

Others prefer to have a bigger pump, and to put either a bypass to the sump to re-oxygenate the water or simply a valve on the return line to slow down the flow to match the overflow. I don't like this approach for two reasons. First, it costs more to buy the pump, and costs more to run the higher GPH pump over time. Secondly, if something happens to the overflow and flow rate slows, you're more likely to overflow the tank. The nice thing about this approach is that if you upgrade to a larger tank later, your new pump might work for that tank too.

Neither way is right or wrong. What makes sense to you, and works for you is the right way for you.

A properly configured system that is properly refilled after a water change won't overflow the sump.

Put it together, and start messing with it. That's the only way to find out how it will work. Just have a few towels handy just in case :lol:

Hope that helps.


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## fox (Jun 11, 2009)

I tend to use a larger pump and divert back excess flow. It makes for a quieter system.

The system needs to be balanced. If you pump more than your overflows can handle you will need to divert the excess. You can benefit by using this excess to pass thru a UV sterylizer or just allow it to refilter in the drip tray. Cleaner water and more oxygen.

If you overflow more than you can supply you will need to slow down the drain or live with the noise of a cavitating drain. No biggie just restrict the drain and noise goes away. But then you are not getting the amount of flow and added advantages of more turnover of the water collumn. So get another smaller pump and now you can open the drains to compensate. Not a good investment if you had just used a larger pump in the first place.

The larger pump is not a big difference in price when you shop around. I use 600 GPH for 1" PVC as a starting point, though a 1" PVC pipe might flow more under gravity once you add an elbow and or valve you lose some of that flow.


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## KaiserSousay (Nov 2, 2008)

> Put it together, and start messing with it.


Agree..we can fret and worry over every detail on a build and still not cover everything 
Well, I always have something I had not thought of pop up 
If possible, set up a testing area outside, garage, patio, etc. 
A couple of 5 gallon buckets set to the relationship of tank to sump..using tanks water level for height of the top bucket..is a system that has kept my carpet dry and catch some of the mistakes I have made.. 
One big plus of doing this..the wife usually is not hovering over my shoulder while doing a test


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## Mcdaphnia (Dec 16, 2003)

KaiserSousay said:


> > Put it together, and start messing with it.
> 
> 
> Agree..we can fret and worry over every detail on a build and still not cover everything
> ...


 My wife grew up with fish tanks in every room of her house, so she is a good person to have hovering around while experimenting.


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## KaiserSousay (Nov 2, 2008)

> she is a good person to have hovering around while experimenting.


I`ll be at your place on Monday for the trade...
:lol:


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## planenut007 (Mar 21, 2009)

Petsmart.com offers the Quiet one 4000 for around $46.00, I have two of them and am very pleased with thier performance, both are powering sumps with no complaints.
Using the 600gph for one inch, I believe them to be moving somewhere around 700-750
gph @ 4ft. One "U" tube is not enough to keep up with one pump, so I added a second tube.
I do have a flow meter but it only goes to 500gph.


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## Guams (Aug 21, 2009)

KaiserSousay said:


> A couple of 5 gallon buckets set to the relationship of tank to sump..using tanks water level for height of the top bucket..is a system that has kept my carpet dry and catch some of the mistakes I have made..
> One big plus of doing this..the wife usually is not hovering over my shoulder while doing a test


I didn't think of doing it that way. 

I've found that I'm sort of... stuck... right now. The tank that this wet/dry is planned for is already established and set up. I tried working on some of the plumbing yesterday, but came to the conclusion that the wet/dry will need to be put in the stand the properly plumb it... but sand, rocks, water, and a glass tank aren't easy to pull away from a wall. :?

I also learned two things. 1) Kwik-Cut PVC cutters, aren't. 2) After cutting PVC with a Kwik-Cut, slip fit PVC, isn't. I have one 45 degree elbow that I don't think will EVER come off... and I didn't even use PVC cement yet.

Oh, and... thanks for the suggestions everyone. I called around a few more places yesterday and found a Pondmaster 950 that I'll use. I'll have to pick up a few more parts from Menard's in order to be able to divert some of the water flow back into the wet/dry, but it should work out quite well.


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## KaiserSousay (Nov 2, 2008)

> I also learned two things. 1) Kwik-Cut PVC cutters, aren't. 2) After cutting PVC with a Kwik-Cut, slip fit PVC, isn't.


 :lol: 
That`s good...really good
:lol:


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## Guams (Aug 21, 2009)

Bleh, I need some more ideas from everyone, or anyone.

The wet/dry is up and running successfully. There were no floods, which I consider a good thing. :lol:

Anyhow, the pump... the LOUD, LOUD pump! I was able to minimize most of the noise from it by sitting it on top of a scour pad. For the most part it sounds like vibration noise, so does anyone have any ways of silencing/quietening it? I thought about making a makeshift "box" for it out of styrofoam, but the only stuff I have is 2" thick.

And also, where might I be able to buy something like this:



















The siphon tubes I made out of flexible water tubing aren't holding their shape and don't sit flush against the back wall of the tank.

The tubes in the pictures were labeled as "Supreme "King Siphon" tubes in a thread that Hoosier Tank made about his sump. I tried Googling it, but came up empty handed. I also checked around on a few online retailers with the same result.


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