# max flow by standpipe diameter?



## Rick_Lindsey (Aug 26, 2002)

I know the answer's out there, but my search-fu is weak today. Does anyone know where there's a chart showing the max flow for various diameter standpipes? I'm planning to drill my 29gallon for an overflow, with a Quiet One 1200 (probably... haven't bought it yet but it should give about the flow I want). I'd like to be sure my overflow can handle 300gph (more than the pump should possibly be able to deliver), but 29gal is a rather small tank for an overflow, so I don't want to waste space with a gigundous 1.5" standpipe if I don't have to .

thanks,
Rick (the armchair aquarist)


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## Charlutz (Mar 13, 2006)

There is a calculator on reef central. For a straight drain (not siphon)
1" = 600 gph
1.25" = 900
1.5" = 1300


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## Rick_Lindsey (Aug 26, 2002)

Charlutz said:


> There is a calculator on reef central. For a straight drain (not siphon)
> 1" = 600 gph...


Thannks, Charlutz! That's exactly what I needed. According to their calculator I need .72", so i'm thinking 3/4" pvc may work out well for me. I'm planning to have a durso standpipe in the corner of the 29gal tank droping to a 10 gallon directly beneath it on the shelf in the stand (it's a typical "open" stand, but I'm planning to get some ~1/4" plywood and enclose it so my 4 year old doesn't put his bath toys in the sump).

Does anyone know how much flow you lose with a durso standpipe over a straight drain? I could probably use 1" if I needed to, but it seems a bit overkill for this 29 gallon tank (not that a wet/dry sump isn't already overkill for a 29 gallon tank).

thanks,
Rick (the armchair aquarist)


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## Charlutz (Mar 13, 2006)

I'd go with the 1". It's not that much bigger and it gives you a lot of headroom to expand or modify as the case may be. Not much margin for error with the 3/4". Better to have too much drain capcity then not enough.


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## Jerseyfish (Apr 16, 2008)

Be careful about that pump rick! I just got my quietone 1200, and it loses alot of gph really quick. The website shows a different graph then the box (website graph here) At 3 feet its down below 200 gph, and at 5 ft its down to 100 gph, both a foot worse then that it shows on site.

I'm actually going to putting this pump to the test outside tomorrow morning, as I'm designing a wet/dry similar to what you described, with a 3/4" pvc overflow. I'll report the performance of the pump, and my 3/4" pvc as far as their gph then.


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## Rick_Lindsey (Aug 26, 2002)

Thanks for the advice, Charlutz, and the warning, Jerseyfish! I'm very interested in the results of your testing. I haven't measured anything to get a more accurate number on amount of head, but I expect it to be between 3 and 4 feet. If I get >150gph I'll be quite happy with the pump performance, though. I know everyone talks about "10x" filtration, but imho that's for an overstocked mbuna tank with HOB power filters. I'm sure that 5x will be more than adequate with a wet/dry trickle filter and dwarf tanganyikans . Besides, I don't want to be blowing the poor multi's all over the place!

Oh, and Jerseyfish, I'd be very interested in finding out what you think about the noise level of your quietone 1200.

-Rick (the armchair aquarist)


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## Jerseyfish (Apr 16, 2008)

Here's my results. I recorded the time it took to fill a 7.5g bucket, and then converted to gph from there. The pump was pushing through a 3/4" aquarium hose. The values are all rounded off a bit, just fyi.

3.5' got me 135 gph
2.5' got me 175 gph
1.5' got me 220 gph

Quite worse then the graph on the site. As for the volume, its name holds true; It is very quiet. Completely submerged, I couldn't hear while standing right above the bucket it was in. Once the water level reaches it, the noise will then become quite audible.

Also, 3/4" pvc pipe gave me about 370 gph (with two or three 90Âº turns, both came out the same). My 1/2" pvc, which I use as my permanent tank siphon, gives me about 240, with two bends in the piping. Just to give you some actual results.

If you're aiming for 5x on your 29 gallon, and you set about 3 feet of head, you should be able to get away using this pump, and you could probably even use 1/2" pvc if you really wanted to go small.


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