Silent and Failsafe Overflow System

[uncleof6]

Thanks,

The elbow design of the full siphon drain and open drain, will cause the water level to be lower than the tanks in that overflow, like it is now.


But I'll have to figure out how to design the emergency drain so that water is not lower than the tank so I can have flow inside the other overflow. If it had an elbow it would start to function as a drain before the water leveled out.

Make the emergency drain inlet be above the water level of the tank. The water level in the "dead" overflow, will be the same as the water level in the tank. Upturned elbow, taller standpipe.

 

[inky]

Hi all, I've been lurking on this thread for a while now and finally getting the chance to install this system in a new 6 foot tank. Looking at 40mm syphon and open drain bulkheads and a 50mm emergency drain. I think these are correct for the tank size and 5000lph return pump.

A couple of questions have raised their ugly heads....

1) should an overflow box of 150mm height by 300 x 300mm be big enough to fit the internal gubbins? Looking at the plan of 60mm and 65mm holes, it should fit in the 300m length available

2) should I put a weir comb on top? Or doesn't it matter?

Ian

 

[stormrider27]

Yes that would be the one.... i have drawings in photobucket also.


http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

http://www.reefcentral.com/forums/showthread.php?threadid=1310585

1.5" plumbing, but really depends on the flow rate.

What purpose does the vertical glass partition between the full syphon and the emergency drain in the above picture serve? Also, is the height of the external only dictated by the midpoint distance of the internal weir drain holes from the top of the tank? I am asking because I am thinking about having a glass shop cut oval holes in the back of my tank instead of round holes if that will allow me to use a shallower external box The reason I would like a shallower external is that I want to put a shadow box behind the tank and a deep external will lessen the visual effect of the shadow box.

Thanks :beer:

 

[BeanAnimal]

It appears that the vertical partition (open at the bottom) is simply a support gusset to connect the long box to the long tank.

Too shallow and you are going to have problems with the siphon sucking in air...

 

[gweston]

What purpose does the vertical glass partition between the full syphon and the emergency drain in the above picture serve? Also, is the height of the external only dictated by the midpoint distance of the internal weir drain holes from the top of the tank? I am asking because I am thinking about having a glass shop cut oval holes in the back of my tank instead of round holes if that will allow me to use a shallower external box The reason I would like a shallower external is that I want to put a shadow box behind the tank and a deep external will lessen the visual effect of the shadow box.

Thanks :beer:

I am curious about the divider too. It certainly shouldn't hurt any.

I recently drilled my tank and am nearly ready to install the external box and internal weir. 125g 6' tank. 4' long weir. 2' long external box. The weir drains to the external box via two 1.5" holes. The pipes are 1.5" each. Standard bean design.

I wanted to put a 'slot' between the weir and external box rather than holes. But it was FAR easier to drill the holes. I didn't trust myself to cut a slit. I had some issues getting my local glass shop to drill a hole for me, even with me providing them the hole cutter. So I didn't even bother to ask again.

Oval holes: If the glass shop can cut them for you, will likely cost a good bit. Have you considered a number of smaller circular holes in series? If the glass shop can cut you a slit nearly the length of the external box though.. that'd be a great solution too.

 

[stormrider27]

It appears that the vertical partition (open at the bottom) is simply a support gusset to connect the long box to the long tank.

Too shallow and you are going to have problems with the siphon sucking in air...

Bean, your input is always appreciated! Is there a rule of thumb on how deep the box needs to be in relation to the tank size, flow rate or length/depth of the external to prevent the siphon from sucking air?

I am curious about the divider too. It certainly shouldn't hurt any.

I recently drilled my tank and am nearly ready to install the external box and internal weir. 125g 6' tank. 4' long weir. 2' long external box. The weir drains to the external box via two 1.5" holes. The pipes are 1.5" each. Standard bean design.

I wanted to put a 'slot' between the weir and external box rather than holes. But it was FAR easier to drill the holes. I didn't trust myself to cut a slit. I had some issues getting my local glass shop to drill a hole for me, even with me providing them the hole cutter. So I didn't even bother to ask again.

Oval holes: If the glass shop can cut them for you, will likely cost a good bit. Have you considered a number of smaller circular holes in series? If the glass shop can cut you a slit nearly the length of the external box though.. that'd be a great solution too.

I also have a 6' 125 so we will need to compare notes. I have not approached a glass company yet but I will let you know if they are willing to cut oval holes and if so how much.

Good idea on a series of smaller circular holes. If my oval idea doesn't pan out that sounds like a good backup plan!

 

[eagle9252]

Having to change plans on the C2C OF. Since I could not find the 150G (48x30) that was drilled they way I wanted it I went with a 120G (48x24) mostly due to money. I drilled the 120G tank left side center to rear with three 1-3/4” holes.

With the tank sitting about 12” off the front to allow for the pipes and such it did not LQQK good. So with the tank up further I had to slide the tank further from the fixed wall and it’s hanging over the right side of the top for the moment. It LQQKs like I’m going to have to do an external box and come out the bottom for the Bean Animal Over Flow. I can scab on to the stand area so that’s no problem. Just need to get the placement of the drains first.

Here are the questions.

Will the offset three holes be ok? With doing the external box I can do three 1-34 holes for 1” bulkheads. 1st hole from rear would be straight shot down or with fewest bends the OC. 2nd or middle would be slight bends and would be siphon and 3rd close to the center of the tank would have some bends and would be the emergency channel.

Should the pipe size be 1-1/2 on the OC and dry and 1” on the siphon all the way to the sump (36 to 48”) offset and below, per Bean’s suggestion this was on the internal C2C OF? Should I drill another hole in the tank to make it four holes for the water to pass through to go to the external box? the external box should be lower? Where should the 1-1/2 tees middle be as I already have everything inside of the tank in a fixed location.

I was hoping to have water in it the weekend but with have to set the box on the rear if I get it set Thursday night it might be dry by Sunday.

Sorry about the pics it was 5am this morning and the phone was not awake yet. I just stuck the fittings on there to see what it could LQQK like.

 

[gweston]

Having to change plans on the C2C OF. Since
Here are the questions.

Will the offset three holes be ok? With doing the external box I can do three 1-34 holes for 1" bulkheads. 1st hole from rear would be straight shot down or with fewest bends the OC. 2nd or middle would be slight bends and would be siphon and 3rd close to the center of the tank would have some bends and would be the emergency channel.

Should the pipe size be 1-1/2 on the OC and dry and 1" on the siphon all the way to the sump (36 to 48") offset and below, per Bean's suggestion this was on the internal C2C OF? Should I drill another hole in the tank to make it four holes for the water to pass through to go to the external box? the external box should be lower? Where should the 1-1/2 tees middle be as I already have everything inside of the tank in a fixed location.

The offset holes/drains are perfectly fine. No worries there.

I like the slits on the overflow. That cut into glass, or acrylic?

As for holes to the external box. I'd judge the hole size based upon your drain size. If your siphon is 1", a couple 1" holes is plenty. If your siphon is 1.5", a couple 1" holes should still be ok, but I'd think of a third 1" hole, or two 1.5" holes. The idea is to have somewhat more capacity to the external box than the external box actually needs so you know you are making best use of the available flow rate.

The pipe sizes are more up to you than anything. My 125 long is going to have 1.5" drains x3. I could have gone 2x1.5" and 1x1", three 1" pipes, or some other combo. Bean's original design has 1" pipes. Going 1.5" just gives you some more potential flow capacity.

As for the positioning of the external box. You mainly want to make sure that the water level in the external box will stay high enough to keep the elbow submerged, otherwise it might suck in air which is undesirable for the siphon. My external box is the same height as my weir. But both are about 6" deep. So there is some depth to work with. Am installing mine tonight (if all goes as planned).

 

[eagle9252]

it's 1/2" acrylic. the weldon ran some (not happy) but it is what it is.

 

[eagle9252]

what thickness for the external? I can get 4mm (3/16). I just called the glass place and 1/4" (6mm) the want 45.00 the size I gave them was 1pc 8x20, 1pc 4x20 and 2pcs 4-1/2x8 this was just rough off the top of my head. realistly I'm thinking the box 4x6x15 would be long enough

 

[uncleof6]

6mm (1/4") at the very least. 4mm is too fragile. Since you will be using an ADHESIVE silicone yes? You will not have water in it by Sunday, rather 7 days minimum cure time, from the time you assemble it.

 

[uncleof6]

The offset holes/drains are perfectly fine. No worries there.

I like the slits on the overflow. That cut into glass, or acrylic?

As for holes to the external box. I'd judge the hole size based upon your drain size. If your siphon is 1", a couple 1" holes is plenty. If your siphon is 1.5", a couple 1" holes should still be ok, but I'd think of a third 1" hole, or two 1.5" holes. The idea is to have somewhat more capacity to the external box than the external box actually needs so you know you are making best use of the available flow rate.

The pipe sizes are more up to you than anything. My 125 long is going to have 1.5" drains x3. I could have gone 2x1.5" and 1x1", three 1" pipes, or some other combo. Bean's original design has 1" pipes. Going 1.5" just gives you some more potential flow capacity.

Bean's original design has 1" bulkheads, however the pipe is 1.5", the internal elbow is 1.25".

As for the positioning of the external box. You mainly want to make sure that the water level in the external box will stay high enough to keep the elbow submerged, otherwise it might suck in air which is undesirable for the siphon. My external box is the same height as my weir. But both are about 6" deep. So there is some depth to work with. Am installing mine tonight (if all goes as planned).

Water level in both the internal and the external should be the same--at the horizontal centerline of the pass through holes. The height of the external, or "how far the bottom of the external is from the pass through hole centerline", is determined by the plumbing configuration: the height of the assembly--from the seating surface of the bulkhead, to the top of the elbow. It is best to determine the height of the assembly, first, before deciding how deep the external box needs to be, and and final position. The top of the external (on a rimmed tank) should sit at the bottom of the trim on the tank--which should be the same as the internal weir.

 

[eagle9252]

Well could I laminate 3/16" together or I have ½" acrylic I could use. My thoughts on the 3/16" were to have at least a center brace and I would make two braces out of ½" acrylic that are scroll shaped and round the edges over with a router to dress it up some.

 

[eagle9252]

double post

 

[uncleof6]

Well could I laminate 3/16" together or I have ½" acrylic I could use. My thoughts on the 3/16" were to have at least a center brace and I would make two braces out of ½" acrylic that are scroll shaped and round the edges over with a router to dress it up some.

Laminate? Use the 1/4". Do not use acrylic on the outside of the tank. The silicone does not have the ability to serve a structural function when used with acrylic. Don't take unnecessary risks, in the end, they cost more than doing it the right way the first time.

 

[Firochromis]

Hi all,

I've read the first 40 pages before the split and then the 140 pages in this thread, and skimmed the last 40 pages. So, from now on my nick is Firochromis-Reloaded

I still have a question on mind about sizing of pipes. I'll pump some 1500 gallons to aquarium after head loss and have the following on mind:

siphon: 3/4" bulkhead and 1.25" pipes from overflow to sump
open channel: 1.5" bulkhead and 1.5" pipes from overflow to sump
emergency: 3/4" bulkhead and 1.25" pipes from overflow to sump

Probably 1" pipes for siphon would be enough, but since there is a valve on it, I can reduce it a little more, if needed. My overflow is an internal one and bulkheads are on the bottom glass. So, this lines will be straight, no elbows.

Any suggestions on sizing?

Trying my chance once more time

 

[BeanAnimal]

It appears that you are stuck with the bulkhead sizes, so have no options. The siphon diameter is going to be rather limiting and will be very dependent on the total head height. I would not expect to get more than 500 GPH out of it in most real world situations...

 

[gweston]

Trying my chance once more time

I'd run this by a few others before going ahead... but a few ideas?

A> Swap the siphon with open channel. So the siphon runs on the 1.5" pipe? With overflow and emergency on the 3/4? Unsure if this is still considered 'fail safe' should the siphon clog. I'm no plumbing expert.
B> Increase the size of one, or both 3/4" bulkheads. Make them 1" instead?
C> Leave it as it is, but realize the flow limit that Bean mentioned?


GaryW.
==============
'Bir "Gary" Iki Eleri'

 

[BeanAnimal]

I'd run this by a few others before going ahead... but a few ideas?

Yeah, maybe somebody that understands the fluid dynamics can give the right answer

 

[stormrider27]

Yeah, maybe somebody that understands the fluid dynamics can give the right answer

Good thought but what are the chances that would happen? :wavehand: