Stand pipe size??

[cichlid_guy]

ok, i'm building a 150 gal tank.
I'm going to use a dual stand pipe to take water to sump.
what size stand pipe do i need?
to flow about 800-900gph?

Or

what GPH will a 1.25" pipe flow?

scottie

[jeffro426]

It depends on how much pressure your pushing through it...i would say given enough pressure that a 1.25 inch pipe would be enough for 800-900 gallons per hour.

[lee914]

seems tight to me, that would be some decent pressure going through that size tube. I would go with 2" or better

[cichlid_guy]

I don't under stand "PRESSURE"?
stand pipes are not pressureized.
it is a gravity fed stand pipe to the sump.

I am planning on putting 2 - 1.25" pvc stand pipes
the type that when the water is higher then the pipe it runs down the pipe to the sump.

how many GPH can i figure that the two pipes will drain?

I am trying to find out what size return pump i need.
also how big/many stand pipes i will need?


scottie

[jeffro426]

Im sorry, i miss understood your question...im not sure of the velocity of the water coming out of the pipes so its hard to say...im sure theres some mathmatician out there somewhere with the secret formula to figure this out.

[DEmigh]

This sounds like a job for... a physicist familiar with fluid mechanics (not me) or an aquarist familiar with DIY sumps (also not me). Nevertheless, I'll blather a little about math...

When the water level in an aquarium first "crests" the top of a stand pipe, it would seem that flow would be a function of circumference. Under those circumstances, two standpipes with a diameter of 1.25" would provide twice the flow of a single standpipe of the same size. A single standpipe of 2" diameter would provide 60% more flow than a single standpipe of 1.25" diameter.

As the water level in the aquarium gets higher and higher, until the top of the standpipe is completely submerged, the flow rate would become (I presume) a function of the cross-sectional area of the standpipe. Under those circumstances, a single 2" standpipe would provide 256% more flow than a single standpipe of 1.25"

It would seem that (within reason) whatever size pump you buy, the system will reach equilibrium. If the pump empties your sump, just cut a little off the top of the standpipe. If the water level in the aquarium is too high, cut more/deeper teeth in the sides of the top of the standpipe.

If the above assumptions hold, then the decision about what pump to buy becomes more a matter for you to decide. How many times per hour do you want to "turn over" your tank? For a 150 gallon tank, 900 gph is turning over 6x per hour.

[cichlid_guy]

I guess my big question is:
i want to flow 900gph.
what size stand pipes do i need to get this?
there a single set up or dual set ups.

scottie

[Uncle Bete]

Hi,
this will probably be more of stuff to consider. Opposed to an answer to your actual question. But, could help out in your final set-up?
I've built a few pre-filters and various contraption's that have to do with water movement. I haven't done the actual stand pipe thing, but it would be comparable to useing the pipe from a pre-filter.

After I get an idea going... say like a couple of stand pipes in a 150 gal. tank (I don't have one that big... just an example).
I try to think of everything that could go wrong, and make a mess.

Stuff like,WHAT IF, one of the two pipes get's clogged up by something, can the other one handle the extra flow? Or is all the water in the sump going to end up going over the top of the tank?
I tend to go with over kill in this area just for that reason. And I don't see much difference in difficulty of hiding a 1" pipe compared to hiding a 2" pipe.
I have found that when you do run something like a stand pipe on the edge of its capacity it make's alot more noise, and even more noise if the lower(out) end is under water. You get a gurgle, splash, gurgle, splash thing going because it starts to fill up, then the pressure shoves most of it out.

Now lets say you are running them(2) on the edge of not enough.
And the water is 1/2" or so above the stand pipe. And the pump stops running(power outage, etc.) Is the sump big enough to accommodate a 1/2" of water from a 150 gal. tank?
--------------------------------------------

If you haven't got your answer yet for the gph question. You could go down to your LFS and look at some of there pre-filters and ask how many gph they can handle. Thats close to the kind of research I done when I was considering my first per-filter. If they tell you pre-filter A can handle 800 gph, and pre-filter B can handle 1200. Look at the diff. in the size of tubes etc. that they use. Then possibly do like me and go with over kill.

I hope this helps in some kind of way.

Have a nice day!
Uncle Bete

[slipknottin]

1" will flow at least 800 GPH. Over 1,000 as water builds up on top.

1.25" will flow somewhere around 1,250 GPH.


Before you build the standpipes consider using these instead. http://www.rl180reef.com/pages/standpipe/standpipe_frame.htm

[cichlid_guy]

the stand pipe i plan on using is one like the 180 reef.com

So, if i am running Dual 1.25" pipes i can flow over 2400gph?
!!! :) !!! thats what i'm wanting to know!
so if i have a 1000gph pump it can flow full open and it will not over flow the tank!!

scottie

[slipknottin]

I know people that are running dual 1.25" with ~2800 gph and no problems (Ampmaster 3000 running full blast)

[cichlid_guy]

SWEET, thats what i was looking for

scottie