Silent and Failsafe Overflow System

[BeanAnimal]

Mike, for the most part it does not matter how or where the sandpipes exit the tank as long as the basic design principle is follow. In a vertical setup, the siphone would be the bottom hole, the open channel the middle and emergency the top. However, you still want to maximize the amount of linear overflow, no matter what the flow.

 

[dwl]

Hello all,

I am not sure if this has been covered as I was not able to read all 160+ pages of this thread.

Would there be any problem at all with incorporating this into a "standard" in-tank overflow, be it corner or middle, assuming there are 3 holes drilled in it?

If one had a tank with a center overflow box with 3 holes drilled in the bottom of the tank for 1" bulkheads (and maybe a return), could this be used?

One more, if that same center overflow had 2 holes for a 1" bulkhead, and 1 hole for a 3/4" bulkhead, could this be used, and if so, could/would the 3/4" be used for the primary siphon, the "durso" or the failsafe?

Thanks.

 

[nemosworld]

Hello all,

I am not sure if this has been covered as I was not able to read all 160+ pages of this thread.

Would there be any problem at all with incorporating this into a "standard" in-tank overflow, be it corner or middle, assuming there are 3 holes drilled in it?

If one had a tank with a center overflow box with 3 holes drilled in the bottom of the tank for 1" bulkheads (and maybe a return), could this be used?

One more, if that same center overflow had 2 holes for a 1" bulkhead, and 1 hole for a 3/4" bulkhead, could this be used, and if so, could/would the 3/4" be used for the primary siphon, the "durso" or the failsafe?

Thanks.

I would use the 3/4 for the emergency/failsafe drain.
how big is your tank?
what size pump are you running?

 

[TheFishMan65]

If you have 3 holes you can make this work.

 

[MikeInToronto]

However, you still want to maximize the amount of linear overflow, no matter what the flow.

Is this for the sake of silence or safety?

For silence, I think if the drop from the top of the weir to the surface of the water (in the OF box) was about 1/2" there wouldn't be much sound at all. I haven't tried it so I'm not sure. I know that on my 4' tank, the OF is 24" long and this is definitely not enough, but the pump is super huge for the tank.

For safety, a 6x6 box is pretty standard for 600-800 gph flow-through, regardless of OF-design.

A coast-to-coast uses a lot of tank space and short of having an external OF box, I'm not sure I want to waste that much space. But if I go custom, it's definitely something I would try.

I guess this is all moot since your design is the best regardless of how it's put together; I'm just throwing out thoughts

Thanks for the help.

 

[BeanAnimal]

Mike,

The efficiency of the surface skimming (gas exchange, etc) is a direct function of the weir length. The longer the weir, the more efficient the skimming and gas exchange.

The narrow box is likely going to need to have teeth, due to the thickness of the water moving over it. The teeth directly reduce the length of the weir, and therefore the surface skimming and gas exchange.

Noise may or may not be an issue depending on many variables. However high flow over a small area creates a rather deep impact plume that can carry entrained air (bubbles) into the siphon intake and cause noise.

There are few hard and fast rules, some things work better than others, but I am sure you can come to a reasonable point of compromise.

 

[Floyd R Turbo]

In reference to my post # 3025, I'm still looking an answer to a couple questions.

As for #1, is there any issue in making the weir angled, whether it is mad as shown (acrylic) or made of glass and siliconed in place?

I am debating between acrylic boxes with bulkheads as shown on my diagram and glass boxes of similar design (slanted weir) siliconed in place. So that leads me to #4:

#4, is there any reason why it would be a bad idea to not install a bulkhead in hole?

If not, then I could drill smaller holes and have the same flow-through as larger hole with bulkheads.

 

[Floyd R Turbo]

In reference to my post # 3025, I'm still looking an answer to a couple questions.

As for #1, is there any issue in making the weir angled, whether it is mad as shown (acrylic) or made of glass and siliconed in place?

I am debating between acrylic boxes with bulkheads as shown on my diagram and glass boxes of similar design (slanted weir) siliconed in place. So that leads me to #4:

#4, is there any reason why it would be a bad idea to not install a bulkhead in hole?

If not, then I could drill smaller holes and have the same flow-through as larger hole with bulkheads.

 

[Poomba]

I know its supposed to be self tuning, but I just finished my set up and I cant get the siphon dialed in to where it doesnt drain the overflow or cause the level to raise and cause the secondary to go full siphon. Which then drains the whole thing....

 

[scott26]

I know its supposed to be self tuning, but I just finished my set up and I cant get the siphon dialed in to where it doesnt drain the overflow or cause the level to raise and cause the secondary to go full siphon. Which then drains the whole thing....

You want to do very small increments let it set for a min. to see if it settles if not check for air leaks I took me a little while to get it down as well.

 

[TheFishMan65]

Turbo, I was thinking about this and assumed some one else might answer (been out of town and trying to catch up). If you can attach the external box in a water proof mode then the bulk heads are not needed. I don't see why an angled weir would present a problem (other than cleaning). At least as I understand how this system would work.

Bulkhead aren't bad IMHO just not needed.

 

[TheFishMan65]

Poompa, what is the height difference between the two drains? Maybe a picture.

How far in the sump does the siphon and open terminate. Anything odd in the pipe runs from tank to sump? We need more information!

 

[scott26]

In reference to my post # 3025, I'm still looking an answer to a couple questions.

As for #1, is there any issue in making the weir angled, whether it is mad as shown (acrylic) or made of glass and siliconed in place?

I am debating between acrylic boxes with bulkheads as shown on my diagram and glass boxes of similar design (slanted weir) siliconed in place. So that leads me to #4:

#4, is there any reason why it would be a bad idea to not install a bulkhead in hole?

If not, then I could drill smaller holes and have the same flow-through as larger hole with bulkheads.

I don't see why the angle would be a problem you should try to have a min of 3/4" clearance from the bulkhead elbow to let water pass. As far as the bulkheads go I would say seal it up with silicone and glass less places for leaks with those pesky bulkhead gaskets.

 

[MikeInToronto]

As for #1, is there any issue in making the weir angled, whether it is mad as shown (acrylic) or made of glass and siliconed in place?

I thought about this myself, before. I don't see why it wouldn't work.

#4, is there any reason why it would be a bad idea to not install a bulkhead in hole?

If not, then I could drill smaller holes and have the same flow-through as larger hole with bulkheads.

It took me a bit to figure out what you were asking here. The only reason I would put a bulkhead in the hole is because of the properties of glass. Just like with a nicked windshield, if there is a tiny imperfection, it doesn't take much to turn it into a crack. If it were my tank and I didn't want to use bulkheads, I'd use those Uniseal bulkheads; they use less space but keep the glass safe. In fact, I think I might just do this myself. Thanks for the suggestion!

 

[Poomba]

Here are some pictures of my system. Right now its regulating pretty well, but with the hose underwater but not sucking water up.

 

[TheFishMan65]

Poomba, no expert but I think the siphon (closest to center?) is to far under water. Since you have union can to switch it with the open and take out the coupler and see if the works better.

Do you have a better picture of the drain in the tank.

ALSO, you probably should support the plumbing better if you have not already.

 

[Poomba]

The full siphon is too far underwater?
I will probably just cut it a bit. That would be easiest.

And as far as supporting it, one I have the plumbing figured out there is a piece of wood that will hold up the horizontal piece, and the Pipes are going to be tacking into the stand where the second 45 is.

 

[afgun]

Rule of thumb we've discussed before is 1/2" to 1" under water. Mine are about 1" and starts just great

 

[Poomba]

The problem isnt starting, its getting the flow to match the water coming into the overflow

 

[Floyd R Turbo]

IThe only reason I would put a bulkhead in the hole is because of the properties of glass. Just like with a nicked windshield, if there is a tiny imperfection, it doesn't take much to turn it into a crack. If it were my tank and I didn't want to use bulkheads, I'd use those Uniseal bulkheads; they use less space but keep the glass safe. In fact, I think I might just do this myself. Thanks for the suggestion!

That's what I was concerned about - a chip in the edge of the hole. I wondered how much I should worry about that possibility.

That being said, I've seen builds throughout this thread where rectangular holes rounded on the ends were cut, slots cut, etc and those (the interior cut edges) are not 'braced' by bulkheads, and they appear to work fine. So why not with a circular cut? I know that the issue then becomes the cut-through point, where the drill bit breaks through the other side. Flipping the bit to the other side might assist.

Otherwise, I could use a diamond tip dremel and bevel the edges or smooth out any chips maybe?

The other thing is that if the bulkhead would serve only to protect the edges of the hole from further damage, then I could cut the bulkhead threading off on the nut side so minimize the space taken up. That way I could put the nut end on the slant weir side and it could be removable if I ever needed it to be.

Would the Uniseal bulkheads offer the same protection? I would think not. I considered your statement about how it wouldn't take much for an imperfection to become a crack, and I could see the bulkhead providing support so that doesn't happen.