Plumbing question

[grassi]

What is gonna be the flow rate of an overflow made of an upside-down 90° 2'' Pvc elbow?

Trying to figure out the needs of a new tank...

[RedCloud]

hope this helps

 

If you dont put an air intake on the back top side of the plmbing it will creat a siphon and rise and lower over and over. If you build it like a durso on the outside of your tank it will depend on the size of air hole you drill in the top cap.

[grassi]

Yes, I was thinking about an external durso. The noise is not a big concern. No idea about the flow range I can get.

[andy]

2"?! Dang, more than you can easily pump back up to the tank. I've run 600gph easily through a 3/4" 90-degree, and the 2" is >5x the cross-sectional area so around 3000gph.

[RedCloud]

I think this chart on the gravity flow column would be relative to the pipe compleately full without air, like a siphon. That might be able to give you a idea, with an absolute max flow rate.

http://www.flexpvc.com/WaterFlowBasedOnPipeSize.shtml

[Smann]

If you are starting from scratch check out this thread, go back to the beginning to see the original design

http://www.reefcentral.com/forums/showthread.php?t=1541946

 

I did this on my frag tanks and also just put it in my 180 inside the center overflow

[grassi]

2"?! Dang' date=' more than you can easily pump back up to the tank. I've run 600gph easily through a 3/4" 90-degree, and the 2" is >5x the cross-sectional area so around 3000gph.[/quote']

 

Yes 2''. I got an used frag tank with an hole for a 2'' bulkhead. Also I was gonna upgrade my Little Giant with an Hammerhead which is rated for more than 4k @ 0ft.

I was thinking of using the Hammerhead for bot the display tank return (where I'm using now about 1000gph with 2 bulkheads, but I could also add a third one and get rid of one powerhead) and the frag tank return. I could have 4 bulkeads in the frag tank and so I have no need of other flow.

Even if I'm not using the hammerhead at all its power, it is just gonna run low on amps.

What do you think?

[grassi]

Thanks for the link Redcloud. Reading that number let me think that some 2000gph is a possible flow rate. Going back with 4 returns of about 500gph each should generate a nice flow. If the flow is gonna be too much I can just put some lock lines to better direct the flow and create some friction..

 

Smann, I remember your frag tank build!!! Unfortunately I'm not starting from scratch.

But it is probably gonna be the drain design for the day I'm gonna start building something "big" :-)

I have to fit this proptank in my existing system, which is not the best ever designed. I have a small sump, not enough space (in height) for a good gravity feed and a very small stand.

In fact I'm still torn about attaching it to what I already am running or set up a new system for the propagation.

[RedCloud]

no problem, lets see some pics when your done.

[andy]

I'm in the low-flow-through-the-sump club. My rule of thumb is roughly 3x tank volume in gph through the sump, give or take. Much more than that is wasted electricity IMO.. after all, why run more water through your sump than you can run through the skimmer? You'll just be recirculating unfiltered water and I don't see the point in that -- better to get that circulation from more efficient (and quieter!) stream-style powerheads or a closed loop.

[Mandinga]

plug in the pump and find out!

 

(whistle)

[grassi]

I'm in the low-flow-through-the-sump club. My rule of thumb is roughly 3x tank volume in gph through the sump' date=' give or take. Much more than that is wasted electricity IMO.. after all, why run more water through your sump than you can run through the skimmer? You'll just be recirculating unfiltered water and I don't see the point in that -- better to get that circulation from more efficient (and quieter!) stream-style powerheads or a closed loop.[/quote']

 

Your point of view does make a lot of sense, I agree.

But sometimes depends on particular setups and preferences. I have a closed loop too but I like to run a lot of water in the sump for many reasons: I can have more water contacting the skimmer area, I drip Kalk in the sump with a Ato and I like to dissolve as fast as I can, I also have a fuge as a part of the sump and also carbon and gfo reactors. Also there is much more air in contact with water in the sump.

[grassi]

plug in the pump and find out!

 

(whistle)

 

hehehehe.... if you then will help me cleaning the mess I can do that ;-)