overflow surge device

orthokardia · 01/10/2010, 07:11 PM

I need input on a reverse surge design. I have been throwing the idea of puuting a toilet flapper in the overflow. I will have a 2" line that Ts into two 4" overflow tubes. the taller tube would be the max water level and serve as a murphy block just in case. the shorter overflow would be the desired water level change below the taller one. the difference will be less than the sump capacity. a toilet flapper will be threaded into the shorter tube and will have a float that should fire it when it reaches the max desired water level. the water should then rapidly drain to the level of the lower overflow.
Am i crazy?

kgross · 01/10/2010, 08:51 PM

I don't see how that is going to cause a surge in the main tank, unless you bring the water level up above your overflow box before the surge goes.

But a picture/drawing might explain better.

Kim

Mikep503 · 01/10/2010, 08:54 PM

I agree, but it might not be a bad idea for the return wich feeds my frag tank

. Keep the idea rolling.

orthokardia · 01/11/2010, 06:10 AM

http://s757.photobucket.com/albums/xx215/orthokardia/tank%20shots/?action=view&current=differentialdump.jpg

The float would not lift the flapper until the water level had risen 3" above the overflow. this should give a 30 gal flush that is just less than my sump can handle. this can be adjusted by varying the chain length. the tank is ~300 gal. i hope the drawing comes through. it is my first photobucket. I am also thinking a 2" just in case overflow might be adiquate.

orthokardia · 01/11/2010, 06:30 AM

orthokardia · 01/11/2010, 07:03 PM

I am thinking a 2" failsafe overflow might be large enough. I will be pushing less than 1200 gph. I am running an iwaki 55 with about 10' head

shroutk3 · 01/11/2010, 07:48 PM

won't this just create a surge in the sump? I understand the design, just not sure that the change is going to create any turbulence in your display.

orthokardia · 01/11/2010, 09:06 PM

it is my hope the shear force of the water rapidly flowing across the tank and into the overflow should set up a standng wave. i could be wrong though.....it happens often

orthokardia · 01/12/2010, 04:30 PM

the water level change in the display tank will result from a regular surge tank surging deep into the display tank.

shroutk3 · 01/12/2010, 10:44 PM

so, theres a surge into the display, and then the display surges into the sump??
Still not really sure that the water leaving through the overflow will cause any displacement for things at the bottom of the tank. It would have to fire over very short periods of time, which isn't what happens with the toilet style surge devices from what I've seen.

Just so you know, I'm pretty sure that the toilet style surges require special plumbing- something about back pressure and such

TellyFish · 01/13/2010, 12:48 AM

Wont that simply "flush" your overflow compartment? I don't see why the outgoing flow from your tank would increase?

Flanders · 01/13/2010, 06:33 AM

I could be wrong, but I suspect you wouldn't get anything approaching a wave. also, you'd have to have the overflow at least 3 inches below your maximum water level. I personally wouldn't want the water level that low in my display tank for aesthetic reasons.

this is a subject I'm interested in, though. I just built one of these surge devices and won't be able to try it out until I can set up my tank which will be at least 6 months.

Flanders · 01/13/2010, 07:39 AM

also, if you're going to try this, after thinking about it I wonder if a reverse carlson siphon device might be better suited to this application. one of the big benefits of the toilet flapper is fewer bubbles which shouldn't matter here, and one of the drawbacks is maintenance. also, I believe the carlson provides a stronger surge.

der_wille_zur_macht · 01/13/2010, 08:11 AM

Surges that involve water rushing through a pipe under gravity siphon (whether a pipe from a traditional "above tank" surge, or your design) are limited by the max flow rate through that pipe. It sounds like the limiting plumbing size in your design will be 2". Anecdotally, I would guess that a 2" siphon won't create a very rapid surge in a tank that big - unless it had a LOT of head pressure on it, which won't be the case here. In fact, I bet it'll be downright unnoticeable.

The problem with any surge device involving a flapper valve is that you're limited by the size of the flapper you can find. Typically, when people are using this sort of design on a large tank, they just add several of them. It would be very hard or impossible to use several flappers in your design, because you'd have to keep them in sync.

If you really want to proceed, I'd look for a design that does not involve flappers - i.e. one of the "constant siphon" designs where there is a standpipe covered by a shroud that preserves the siphon as the water level drops during the surge, then breaks it when the water level is below the opening of the shroud. Then, you'd be able to use large plumbing (like 6") for the drain.

This concept will introduce a host of other impracticalities which I'm sure you've already thought of - for one thing, the sump will be pretty much useless for a skimmer, ATO, or other traditional equipment due to the huge fluctuations in water level.

Another thing to think about - any poor livestock in that top 3" of water is going to end up in the sump! Again, a traditional surge avoids this. Above-tank surges are powered by pumps that can be protected from livestock. Even with an RCSD - if the livestock gets sucked into it, they just swim out as it's refilling with air.

As much as I really LOVE the concept of surge devices, I'm going to use a variable speed closed loop in my 360g instead. No noise, no bubbles, no fluctuations in water level, no extra stress on the tank, and complete programmable control.

orthokardia · 01/13/2010, 04:41 PM

well i finally filled the tank with enoough water for a test and of course you were all correct. the surge was not noticeable. on the plus side the larger volume of water actually made the randomness induced by the daul scwds on the closed loop more pronounced... i still need to skim the top water for my skimmer and i am planning on doing a single beckett driven by the iwaki-55. is there anything i could do with the 800gph-ish output that would be more benificial than returning it to the sump?

shroutk3 · 01/15/2010, 12:33 PM

just direct it around the tank for flow. If you want more power out of it, you could think of adding some penductors to create more flow. Sorry your ideas wasn't everything you had hoped.

DeathWish302 · 01/15/2010, 02:36 PM

Quote:

Originally Posted by der_wille_zur_macht

As much as I really LOVE the concept of surge devices, I'm going to use a variable speed closed loop in my 360g instead. No noise, no bubbles, no fluctuations in water level, no extra stress on the tank, and complete programmable control.

+1

I have to agree, as I've experimented with flappers, carlson & 'silent surge' designs in the 2-5gal capacity and gave up on obtaining a limited bubble addition but an explosive surge. My next in-wall 200+gal build will have liveforphysic's VFD controlled CL.

As for the functionality of your design, I do occassionally turn off my pump and the water drains quickly (per BeanAnimal's overflow system) and have never seen a wave of any magnitude. I can open the valve wide open and little/no change in 'wave' action occurs.

01/10/2010, 07:11 PM	#1
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	overflow surge device I need input on a reverse surge design. I have been throwing the idea of puuting a toilet flapper in the overflow. I will have a 2" line that Ts into two 4" overflow tubes. the taller tube would be the max water level and serve as a murphy block just in case. the shorter overflow would be the desired water level change below the taller one. the difference will be less than the sump capacity. a toilet flapper will be threaded into the shorter tube and will have a float that should fire it when it reaches the max desired water level. the water should then rapidly drain to the level of the lower overflow. Am i crazy? __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/10/2010, 08:51 PM	#2
kgross Premium Member Join Date: Nov 1999 Location: Nampa, ID Posts: 5,870	I don't see how that is going to cause a surge in the main tank, unless you bring the water level up above your overflow box before the surge goes. But a picture/drawing might explain better. Kim __________________ Proud Member of the Idaho Marine Aquarium Society America will only be the Land of the Free as long as it is the Home of the Brave. Current Tank Info: AGA 180gallon tank, VHO/MH lighting, DSB, calcium reactor, Also a 7 Gallon Nano softy tank, and a 32 gallon cube

01/11/2010, 06:10 AM	#4
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	http://s757.photobucket.com/albums/xx215/orthokardia/tank%20shots/?action=view&current=differentialdump.jpg The float would not lift the flapper until the water level had risen 3" above the overflow. this should give a 30 gal flush that is just less than my sump can handle. this can be adjusted by varying the chain length. the tank is ~300 gal. i hope the drawing comes through. it is my first photobucket. I am also thinking a 2" just in case overflow might be adiquate. __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/11/2010, 07:03 PM	#6
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	2" overflow I am thinking a 2" failsafe overflow might be large enough. I will be pushing less than 1200 gph. I am running an iwaki 55 with about 10' head __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/11/2010, 09:06 PM	#8
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	it is my hope the shear force of the water rapidly flowing across the tank and into the overflow should set up a standng wave. i could be wrong though.....it happens often __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/10/2010, 08:54 PM	#3
Mikep503 Registered Member Join Date: Dec 2008 Location: Salem Oregon Posts: 66	I agree, but it might not be a bad idea for the return wich feeds my frag tank . Keep the idea rolling.

01/11/2010, 07:48 PM	#7
shroutk3 Registered Member Join Date: Mar 2009 Location: Ripley, Ny Posts: 315	won't this just create a surge in the sump? I understand the design, just not sure that the change is going to create any turbulence in your display.

01/12/2010, 04:30 PM	#9
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	the water level change in the display tank will result from a regular surge tank surging deep into the display tank. __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/12/2010, 10:44 PM	#10
shroutk3 Registered Member Join Date: Mar 2009 Location: Ripley, Ny Posts: 315	so, theres a surge into the display, and then the display surges into the sump?? Still not really sure that the water leaving through the overflow will cause any displacement for things at the bottom of the tank. It would have to fire over very short periods of time, which isn't what happens with the toilet style surge devices from what I've seen. Just so you know, I'm pretty sure that the toilet style surges require special plumbing- something about back pressure and such

01/13/2010, 12:48 AM	#11
TellyFish Registered Member Join Date: Feb 2006 Location: Chicago 60607 Posts: 1,130	Wont that simply "flush" your overflow compartment? I don't see why the outgoing flow from your tank would increase? __________________ ...and life spirals into astonishing diversity. Current Tank Info: Hawaiian inspired 109g Miracles Rimless - 100g Prop Tank - 300g total system volume

01/13/2010, 06:33 AM	#12
Flanders Registered Member Join Date: Nov 2002 Location: Syracuse, NY Posts: 3,592	I could be wrong, but I suspect you wouldn't get anything approaching a wave. also, you'd have to have the overflow at least 3 inches below your maximum water level. I personally wouldn't want the water level that low in my display tank for aesthetic reasons. this is a subject I'm interested in, though. I just built one of these surge devices and won't be able to try it out until I can set up my tank which will be at least 6 months. __________________ Insert witty phrase, followed by explosive laughter Current Tank Info: 75 gallon reef, two 175-watt MH, two vho actinic

01/13/2010, 07:39 AM	#13
Flanders Registered Member Join Date: Nov 2002 Location: Syracuse, NY Posts: 3,592	also, if you're going to try this, after thinking about it I wonder if a reverse carlson siphon device might be better suited to this application. one of the big benefits of the toilet flapper is fewer bubbles which shouldn't matter here, and one of the drawbacks is maintenance. also, I believe the carlson provides a stronger surge. __________________ Insert witty phrase, followed by explosive laughter Current Tank Info: 75 gallon reef, two 175-watt MH, two vho actinic

01/13/2010, 08:11 AM	#14
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	Surges that involve water rushing through a pipe under gravity siphon (whether a pipe from a traditional "above tank" surge, or your design) are limited by the max flow rate through that pipe. It sounds like the limiting plumbing size in your design will be 2". Anecdotally, I would guess that a 2" siphon won't create a very rapid surge in a tank that big - unless it had a LOT of head pressure on it, which won't be the case here. In fact, I bet it'll be downright unnoticeable. The problem with any surge device involving a flapper valve is that you're limited by the size of the flapper you can find. Typically, when people are using this sort of design on a large tank, they just add several of them. It would be very hard or impossible to use several flappers in your design, because you'd have to keep them in sync. If you really want to proceed, I'd look for a design that does not involve flappers - i.e. one of the "constant siphon" designs where there is a standpipe covered by a shroud that preserves the siphon as the water level drops during the surge, then breaks it when the water level is below the opening of the shroud. Then, you'd be able to use large plumbing (like 6") for the drain. This concept will introduce a host of other impracticalities which I'm sure you've already thought of - for one thing, the sump will be pretty much useless for a skimmer, ATO, or other traditional equipment due to the huge fluctuations in water level. Another thing to think about - any poor livestock in that top 3" of water is going to end up in the sump! Again, a traditional surge avoids this. Above-tank surges are powered by pumps that can be protected from livestock. Even with an RCSD - if the livestock gets sucked into it, they just swim out as it's refilling with air. As much as I really LOVE the concept of surge devices, I'm going to use a variable speed closed loop in my 360g instead. No noise, no bubbles, no fluctuations in water level, no extra stress on the tank, and complete programmable control. __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

01/13/2010, 04:41 PM	#15
orthokardia Registered Member Join Date: Dec 2009 Location: manchester, tn Posts: 1,139	well i finally filled the tank with enoough water for a test and of course you were all correct. the surge was not noticeable. on the plus side the larger volume of water actually made the randomness induced by the daul scwds on the closed loop more pronounced... i still need to skim the top water for my skimmer and i am planning on doing a single beckett driven by the iwaki-55. is there anything i could do with the 800gph-ish output that would be more benificial than returning it to the sump? __________________ 185 gal SPS "The Pheonix", 300 gal SPS Dominant "Remember the signs" - C.S. Lewis The Silver Chair

01/15/2010, 12:33 PM	#16
shroutk3 Registered Member Join Date: Mar 2009 Location: Ripley, Ny Posts: 315	just direct it around the tank for flow. If you want more power out of it, you could think of adding some penductors to create more flow. Sorry your ideas wasn't everything you had hoped.