Silent and Failsafe Overflow System

[BeanAnimal]

There is no need to use Sch.#80 plumbing... #40 or even SDR-21 will be fine and allow for much less restriction.

A quality 36" level used during installation is the easiest if you are installing the overflow to an upright tank. Most folks use blocking and shims under the overflow to raise it to the proper height. This could be as simple as a few cut pieces of 1x or plywood and a few shims.

That said, water seeks its own level, so you could place the tank in its final location and fill it with water to check if the trim is true or not. Mark accordingly with tape or a sharpie and then lay the tank on its back and install the overflow.

There are many posts here about bulkhead hole location. Keep them at least 2 hole diameters apart and at least 1.5 hole diameters from the top. Several people have posted their measurements in this thread.

 

[Poomba]

So if I already have the plumbing do you think I should return it?
I bought it all from BRS and thought since thats what they offered it was what was appropriate.

 

[BeanAnimal]

It will not hurt anything and is more trouble to return than it is worth. In the future, there is no need to purchase schedule 80 fittings or pipe

 

[1234]

Bean

I'm helping a friend with his new build and I'm thinking of having him use 2" for the Bean Animal. His tank will be 72" x 27" x 47.5" with a 48" external overflow. Either that or use x2 1 1/2" as you suggested on your web site, but as you mentioned balancing between the two will be hard. See any problems?

 

[SkyReef]

Ive started to put together the plumbing for my 75 gallon display tank, which is feeding into a 40br sump. Using 1.5 inch schedule 80 plumbing.

How do I make sure the coast to coast overflow is level in the tank, without using a level?

Can I measure from the trim down?

My other question is how do I determine the placement of the holes for the bulkhead?

Hey, Poomba:

When I installed my Coast-to-Coast/Calfo overflow box, I used some CDs stacked up (in their cases)...I confirmed that the stand was level, adjusted it to make it level, then I confirmed that the stack of CDs was level. Then I just installed the overflow box, while it rested on the CDs. That's another example of using shims beneath, as Bean describes.

 

[marius880]

Sorry if this has been answered. But can a 1 inch pipe create siphon to accommodate 1500 gph? Can the pipe get that much water through it before the open channel kicks in ?

 

[golf nut]

Sorry if this has been answered. But can a 1 inch pipe create siphon to accommodate 1500 gph? Can the pipe get that much water through it before the open channel kicks in ?

Here you go.

http://www.beananimal.com/articles/hydraulics-for-the-aquarist.aspx

 

[marius880]

Here you go.

http://www.beananimal.com/articles/hydraulics-for-the-aquarist.aspx

Thank you. That answered my question...

 

[afgun]

Oops

 

[NEK-ap24]

I have a question about an external box to run a Bean Animal drain from.

It seems to me that the space for the plumbing behind a tank takes up valuable realestate that could be used for an external overflow box, then use Bean's drain system from that.

Bean I believe that I read that you are a fan of the aesthetics of the external option.

I have an existing Osaka 260L aquarium with a perfectly good back on it, however I was wondering if anyone has any reason why I couldn't or shouldn't remove the back and have a glass shop cut a weir out of it, and then silicon it back on?

My tank is only 17.7 inches front to back, so I am concerned that an internal box will shadow too much of my aquascaping. If I am already pulling my tank 6 inches off the wall to make room for the big 1.5" True union ballvalves I got, it seems to make great sense to use that space for a 6 x 6 C2C overflow box.

I saw a rendering from Shaggss in a thread called "external overflow design", but was unable to copy and paste it here.

If it is acceptable to do this to the back wall (which is not tempered) how deep should the weir be on a coast to coast plan?

Would it be better / easier to cut the weir without removing the back first? if so any recommendations on what to use to do it? the tank is 41" wide with a small center brace, otherwise is rimless.

Are there any plumbing issues that this may bring up?

Thanks in advance, I do appreciate the vets advice so my rookie project doesn't die an ugly sloppy mess.

 

[BeanAnimal]

I would never take apart a functioning aquarium to alter it. You always run the risk of chipping panels, having seal and seal strength problems. That said, I am sure if you take your time and use the proper materials, you can pull it off.

The weir can be cut on-tank using a continous diamond blade in a circular saw. You would cut the corners first, using a diamond hole saw and then connect the holes with a straight line. Care needs to be tank so that the weight of the drop piece does not allow gravity to break it off (cracking the tank) before you finish the cut.

The weir height needs to be high enough to set the water level at the bottom of the trim or higher.

No plumbing issues, the system works the same internally or externally and is in fact more adjustable (not that it needs it) if it is external through the bottom of the box.

 

[medicreefer]

Long horizontal runs may prevent the open channel from running properly. Increasing the horizontal pipe diameter (to allow free air space above the channel) is not a bad idea, nor is using a sweep to transition from vertical to horizontal.

The effect on the siphon rate is purely a function of the added resistance created by the longer pipe run. While it will reduce the overall flow rate, it will only be by a small percentage for any reasonable length run with reasonable sized pipe. You may or may not hear the water running though the horizontal open channel pipe (many variables).

The bigger issue may actually be getting the siphon to start in a reliable manner. Too large a pipe and the velocity will not be enough to move (purge) the entrained air, or even fill the horizontal run. Too small a pipe and the the system can easily air lock. You may have to play around with different configurations.

The adjustment valve should be at the sump end, otherwise the horizontal run on the siphon standpipe will tend to run partially full and not at a siphon (again based on many variables).

Thanks for the help and info Bean. I think I may have a partial solution to my long horizontal run problem, but I can't figure out how to make it work exactly... My 10 foot horizontal run doesn't have to be completely horizontal. The point where the pipes have to enter the wall (the start of the 10 foot run) is about 10" higher than the top of the water level in my sump. Assuming that I'll have a 5" vertical section of pipe right above the sump for the final drop into the intake section, that would still leave me with the ability to angle my PVC drain pipes such that the pipes drop 5" over the 10 foot horizontal run. So... it wouldn't be completely horizontal and thus would hopefully prevent the problems associated with long horizontal runs you've mentioned above. The pipe would be dropping 1/2" per foot which is actually above code for home drainage plumbing (1/4" per foot).

The problem: how do I get my PVC to run at that shallow of an angle (less than 3 degrees)? There are no fittings for that and I'm thinking simply forcing them to run at an angle would cause problems because they wouldn't be seated properly in the fittings. Any ideas?

 

[afgun]

The problem: how do I get my PVC to run at that shallow of an angle (less than 3 degrees)? There are no fittings for that and I'm thinking simply forcing them to run at an angle would cause problems because they wouldn't be seated properly in the fittings. Any ideas?

Short sections of flexPVC joined with your slightly angled pipe using couplers. It can bend at the shallow angle you're looking for. Or if you have access to a PVC heater, you can use it to make the slight angle you're looking for in rigid pipe.

Home improvement stores sell FlexPVC for a couple bucks per foot. A good quality PVC bending heater will set you back a lot more.

 

[TheFishMan65]

IMHO 1/2 inch per foot the pipe will bend. How do you think they get the 1/4 per foot for code? It would not surprise if if you just picked it up and the other end dropped 5 inches (upto 1 inch maybe 1.5 inches). Boiling water will make PVC bendable. If you are really concerned plump and then cap the low end, fill with boiling water and lower the end to where you want it. Lets it sit till the water cools. No matter what you need to support it periodically or I bet the water weight would bend it more.

 

[medicreefer]

Thanks for the help and info afgun and fishman.

The only thing I was worried about re just letting the pipe bend on its own to get the drop I wan was whether it would still seat correctly. If it does, then great. If not, the flex PVC idea is perfect. Hadn't thought of that.

Now I'm just looking for an opinion from Bean or one of the others experienced with this system on whether or not this gradual drop will help out with the problems I'll be facing with this 10 foot almost horizontal run.

 

[Brwestern]

I'm in the process of my first tank and am about to get a custom tank made. Rimless 45x24x24.

I've decided I want to use this drain method, and really don't know how to have them pre drill and install an overflow.

What would be a way for me to tell the builder how I want my drilling and overflow box setup?

Should I go with a coast to coast or something the size of the 1500 glass holes overflow?
"ideally"' I want something in the tank with a small footprint, but don't know at all.

Can anyone help?

 

[BeanAnimal]

While I can rattle off some answers to your questions, you would be much better served spending an hour or two reading the project description at my website and as much of this thread as you can get through. It will answer your questions and give you a much better understanding of what you will need and why. You will then be able to explain exactly what you want to your tank builder, and/or show him specific photos or posts from my site or this thread.

 

[BeanAnimal]

Thanks for the help and info afgun and fishman.

The only thing I was worried about re just letting the pipe bend on its own to get the drop I wan was whether it would still seat correctly. If it does, then great. If not, the flex PVC idea is perfect. Hadn't thought of that.

Now I'm just looking for an opinion from Bean or one of the others experienced with this system on whether or not this gradual drop will help out with the problems I'll be facing with this 10 foot almost horizontal run.

As I said in my initial response, there are a LOT of variables that will come into play. You may find that you have water noise in the open channel and/or that the siphon is hard to start based on how things shake out.

 

[Brwestern]

While I can rattle off some answers to your questions, you would be much better served spending an hour or two reading the project description at my website and as much of this thread as you can get through. It will answer your questions and give you a much better understanding of what you will need and why. You will then be able to explain exactly what you want to your tank builder, and/or show him specific photos or posts from my site or this thread.

Thanks. I read your website quite a few times, and know you did a coast to coast overflow, I just don't really know enough either way to make a decision on my own. I understand the drain method pretty well, just not the actual overflow (depth and length).

I'm getting through as much of this awesome thread as I can, but I've gotten to where everything is just theory to me, and since I'm ordering my first tank, I don't really have the ability to tinker and see whatnworks best for me.


My basic idea is this, but I just don't know dimensions and what will be sufficient.

 

[BeanAnimal]

Why not have the back wall built lower so that it can act as a natural weir and install an external overflow box?

Is this a glass or acrylic tank?

In general, you want to have as much linear overflow length as you can fit into the tank. Certainly there is a point of diminishing returns, but contrary to common belief and the calculator here at RC, the lower the the flow rate the longer the weir needs to be to provide sufficient surface skimming.