# DIY Overflow Drain Bulkhead



## jdcook72 (Sep 12, 2006)

I’ve been looking for a bulkhead solution for overflow drains for my tank and saw some good suggestions in the forums. I thought I’d add what I came up with as well. My main issue was wanting to drill as small a hole as possible and still have good drainage. All of the small bulkheads I’d seen required 1 1/8” hole and I thought the fittings themselves were kind of, well, bulky. My solution doesn’t shave much off of that but it will use fewer parts overall as I won’t need to add an elbow.

It uses three pieces: 1/2” female pipe X 1/2” barb 90º (plumbing – Lasco D2609), 1/2” male terminal adapter (electrical – Carlon E934D) and an o-ring. I got these at the local Ace hardware store, sometimes this type of place works better than a Home Depot for small pieces, parts and fittings – more selection and I don’t have to buy a bag of 10 of something. I’ll put a piece of extra window screening or a bit of sponge/foam inside the inner piece to filter out debris. Using the electrical adapter was the key as nothing in the plumbing section had a shoulder on it to flush up to a gasket to make a seal inside the tank. Their both PVC.

There should be plenty of capacity as I’ll only be catching overflow from misting a few times a day and some occasional spot watering for plants. I haven’t installed these yet so I don’t know for a fact that it will work but I can’t see that there would be any issues with it.

TOTAL FOR TWO FITTINGS WAS $5 AND SOME CHANGE 8)


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## defaced (May 23, 2005)

That's an excellent solution. 

For anyone not familar with thread specifications, pipe thread is tapered where as electrical thread isn't. They have the same nominal diameter and tpi, but with the male electrical thread you're able to actually thread it completely into the female pipe thread (the right part of his pic where the parts are assembled). If you used two pipe threads, you wouldn't be able to thread them completely into each other which would leave a huge gap between the two parts.


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## spydrmn12285 (Oct 24, 2006)

Does anyone know where I could get this other than ace and what it could be called? I tried this solution, but it seemed the hole was too big for the parts...so they essentially came through the hole. I returned it, and forgot what the brand was. Do I need to glue it in with silicone? Essentially, how do you install?

Thanks!


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## jdcook72 (Sep 12, 2006)

What hole was too big for which parts? You could try a Home Depot, Lowes, Coast to Coast or any hardware store that carries basic plumbing and electrical supplies.

I don't know that the pieces have any name other than their description. Remember that the piece with the 90º bend will come from the plumbing section but you'll have to go to the electrical section where the conduit, boxes and wiring is to find the other piece that screws into it.

I don't know how I could be any more detailed?  

I drilled the holes in my tank to match the size of the parts after I bought them, I'm pretty sure they were smaller than 1 1/8". If you've already drilled your tank and that is what the parts are going through then I you'll have to go with something larger.


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## VanillaGorilla (Mar 11, 2007)

spydrmn12285 said:


> Does anyone know where I could get this other than ace and what it could be called? I tried this solution, but it seemed the hole was too big for the parts...so they essentially came through the hole. I returned it, and forgot what the brand was. Do I need to glue it in with silicone? Essentially, how do you install?
> 
> Thanks!


that is the big 'issue' with installing these rather than true bulkhead's... the holes must be drilled accuratetly to ensure proper fit.. bulkheads seam to have a larger shoulder to compensate...

Try ANY hardware store, as these parts are fairly common.


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## defaced (May 23, 2005)

I can guarantee this is more than you wanted, but I'm bored and had an unfinished tank that had this installed so it was easy to photograph. 

I do mine a similar way, but the part is an off the shelf item at large hardware stores in their electrical conduit section. This stuff is originally used for flexible conduit to join it to a junction box. They come in straight and angled, and in 1/2" and 3/4" sizes. The price is right around 2.50 each for the 1/2" angled (shown below). 


















The hole diameter you need to mount these is .825" (just over 13/16"). That works out to about 21mm. I'm currently using a 22mm bit, but to help center the bulkhead I also use a smaller o-ring (#30 from Lowe's, 7/8" OD, 3/4" ID, 1/16" thick) in addition to the large o-ring that comes with the bulkhead. I'm not sure if I would advise getting a smaller bit and reaming your hole to get the correct size as opposed to the o-ring solution or not. The shorter time I spend with the bit touching the glass the less on edge I am, but the o-ring does add about 15 cents to the project and it's another thing to track down, so.... 














































I want to be able to rotate mine as I don't have a drain system yet, so I crimp the threads of the nut to help keep is from backing off the bulkhead if I turn the whole thing the wrong direction. This is how I provide an on and off to the drain right now. If you wanted to, you _might_ be able to PVC cement this on since this is made of PVC, but you may melt the o-ring, so I'm not sure. 




























To hook this up to a system, I'm going to use the ID of the fitting. It's not a perfect fit to off the shelf tubing, but with a little bit of silicone it works. The OD of the fitting does fit off the shelf tubing, but for what I'm doing it's too big. The ID and OD are .53" (13.5mm) and .61" (15.5mm) respectively. 










I mount my bulkheads so that the water level sets just below the false bottom. This allows the tank to hold alot of water to help temperature stability, but if I need to drain it completely, I simply tilt the tank back and I can drain a good bit of the water out. Enough to move the tank easily.


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## spydrmn12285 (Oct 24, 2006)

Wow, thanks for the replies everyone. I guess my main issue is that I might have drilled too large a hole for everything to be snug. I was just trying to find some sort of remedy for it. 

Argh, so Mike, is my 1 1/8 inch hole too large for that fitting? Or can I use an even larger o-ring to make the fitting snug so that I can't putt the entire piece out one way from the hole?


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## defaced (May 23, 2005)

Yes, that 1-1/8" hole is too big. The OD of the o-ring that comes with the fitting is just slightly larger than that. I would be to look for a bulkhead that needs a 1 1/8" (or larger, and just ream it to fit) hole. In the end, you're not going to find a DIY solution that's going to be cheaper/easier.


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## spydrmn12285 (Oct 24, 2006)

OK, Thanks. I guess I'll just have to bite the bullet and order a bulkhead online. I'll definitely hold on to this thread for future projects.


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## pl259 (Feb 27, 2006)

Anyone bother to do bulkhead drains with the elbow on the inside like this?









Seems to me it would help to drain off more of the nasty stuff near the bottom rather than the cleaner water on top. It would also allow for a siphoning action.

Just a thought...
EricG.NH


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## defaced (May 23, 2005)

Interesting idea, but it's not going to pull anything off the bottom of the tank unless you manually initiate the siphoning action. The area of the bottom of the tank you're going to be able to clean is directly related to siphoning height and drain/tube diameter.


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## pl259 (Feb 27, 2006)

> ...it's not going to pull anything off the bottom of the tank unless you manually initiate the siphoning action.


I respectfully disagree(but can be convinced otherwise). Even without a siphon, it will pull some amount of water from the bottom part of the tank. A drain with no internal elbow will "skim" most of the water from the top surface. Adding a flange to the bottom of the elbow should direct even more water to come from the bottom. With a siphon, an internal elbow should allow the water level to be drained lower than the height of the hole.



> The area of the bottom of the tank you're going to be able to clean is directly related to siphoning height and drain/tube diameter.


Agreed. I was never expecting the elbow would drain all of the bottom water, just keep from draining a lot of the cleaner fresher water on top.

I'm also not a big fan of these dripping bulkhead type drains and would probably add a valve. Properly done, I think you could get the siphoning action for free. 

EricG.NH


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## defaced (May 23, 2005)

> I respectfully disagree(but can be convinced otherwise). Even without a siphon, it will pull some amount of water from the bottom part of the tank.


It will pull water from the bottom of the tank, true, but you need enough water velocity to pick up a particle and move it which is what I was getting at. I am fairly comfortable saying that with the water flow rates we're going to get from our only water input into the system, misting, that sufficient velocity will not be achieved to move any solid object of interest (sand, debris, etc) up and out of the tank. 



> I was never expecting the elbow would drain all of the bottom water, just keep from draining a lot of the cleaner fresher water on top.


This assumes there's something keeping the new and old water from mixing. I'm doubt that's the case as from a mechanical view point, something as simple as a falling water droplet creates mixing when it hits the surface of the water. 

There's also the statistical view point when when we mist we're only introducing say 1 floz of water into a 1 gallon reservoir (1 low flow nozzle in a horizontally oriented 10g tank). Those are steep odds against moving new water out of the system. 



> I'm also not a big fan of these dripping bulkhead type drains and would probably add a valve. Properly done, I think you could get the siphoning action for free.


Yes, by manually controlling when water leaves the system you could get siphoning for free.

Why are you not a fan of drip drains?


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## pl259 (Feb 27, 2006)

> It will pull water from the bottom of the tank, true, but you need enough water velocity to pick up a particle and move it which is what I was getting at.


Completely agree. I guess I was kinda loose when I said "nasty stuff". I'm not really thinking about the heavy particulates, but more about the solutes. I'd like to have a drain system that drains off more of the old water rather than the new.



> This assumes there's something keeping the new and old water from mixing


Not at all. I fully expect they will mix. However, the mixing is not instantaneous, but the overflow is, or nearly so. Statistically, the new water is not yet uniformly distributed.

I would venture to bet that if we performed an experiment with a tank with a gallon of water, the different drains, and colored misting water, that the color of the water, after misting(s), with an overflow drain with an internal elbow would be darker in color then the water with a drain without an elbow. I complete SWAG at this point. 

I don't like the overflow drip systems because I believe they promote a lot bacteria growth, and of the care that needs to taken to prevent cross contamination. Automation is great, and I don't have a better/easier way to do it. Yet!

EricG.NH


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## defaced (May 23, 2005)

> Not at all. I fully expect they will mix. However, the mixing is not instantaneous, but the overflow is, or nearly so. Statistically, the new water is not yet uniformly distributed.


So with either design, old water is the first to go out the drain, unless you want to split hairs and consider the possibility of a new water droplet falling directly in front of the drain. 

I'd be interested in seeing the results of a test like that. I think it'd come out as a wash. 

A simple way to remove cross contamination from the system is to create an "open" drain setup. Basically one where the tanks aren't directly connected to a central drain, but instead drop water into a trough (or even a pipe with over sized holes cut in it for access) that then deposits the waste water into a drain. Though, unless you operate your collection like a lab, I highly suspect cross contamination is already taking place.


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## VanillaGorilla (Mar 11, 2007)

It seems to me that you are making something essentially very easy, very hard. 

Why just skim the fresher water on top when the point of draining the viv is to get the older 'stank' water out, which is mostly on the bottom.

AND like someone said, why do you hate drip lines?


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## defaced (May 23, 2005)

All of those points have been covered in Eric and I's previous posts in this thread.


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## pl259 (Feb 27, 2006)

> So with either design, old water is the first to go out the drain, unless you want to split hairs and consider the possibility of a new water droplet falling directly in front of the drain.


An engineer split hairs? Of course we do! Actually I'm thinking more like the new fresh water is uniformly sprayed over the top surface of the water and is skimmed off by the open bulkhead as it's sprayed. 



> I'd be interested in seeing the results of a test like that. I think it'd come out as a wash.


I was hoping you would do the test! I think it'll have to be a thought experiment for now. I'll ask some of techy friends and see what they think.



> A simple way to remove cross contamination from the system is to create an "open" drain setup.


Yea I'm aware of how to set it up, and believe it works to isolate the tanks. I'm just negative about it with the hope that we hobbiests can come up with another way that doesn't result is a big nasty sump with tubes running all over the place. Don't know if there's a better way or not. 
It's just not elegant enough of a solution for me.


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## VanillaGorilla (Mar 11, 2007)

defaced said:


> All of those points have been covered in Eric and I's previous posts in this thread.



I thought it would make me feel smarter to chime in when i did, but the reality is I have the faintest idea when this thread actually blasted off into WTFland. I get the concept but dont get the question. Just put the bulkhead in your leca AREA?

As we fall back to earth, I am going to ask one of you rocket scientist a question: if I use a single 1/4" ID bulkhead for drainage in multiple 20/10 verts, and if each single 1/4" tube drain goes to a 3/8 main drain, and if the inlet was properly filtered, would I see enough of a suction/waterflow to actually accomplish anything, or is that too small. I would like to save some time from reworking something.

And back to JD:
Have you used your setup yet; How is it working and have you seen any problems?


THANKS


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## defaced (May 23, 2005)

> An engineer split hairs? Of course we do! Actually I'm thinking more like the new fresh water is uniformly sprayed over the top surface of the water and is skimmed off by the open bulkhead as it's sprayed.


Yea, we do split hairs, sometimes it's fun other's it's irritating. Anyway, because the water has to first drain through the substrate before getting to the reservoir, so it forms nice big water droplets that aren't uniform in distribution at all. Yes, I've actually stood and watched water drip into my false bottom :? 



> I was hoping you would do the test! I think it'll have to be a thought experiment for now. I'll ask some of techy friends and see what they think.


I knew you were going to say that. If I only had the time. With the end of the quarter coming in three weeks, time is a at a permium. 



> It's just not elegant enough of a solution for me. Very Happy


How does this sound, water sensing circuit and a mechanized valve? When the water is high enough to be able to initiate a siphon the valve opens and your false bottom is drained. 



> would I see enough of a suction/waterflow to actually accomplish anything, or is that too small.


I'm not a rocket scientist, but a welding engineer, you'll have to compromise. What are you trying to accomplish? If you want to move debris, it probably won't work, if you want to move water that'll be fine. Considering water can seep through even the tiniest cracks, I think a 1/4" ID tube would do the job.


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## dragonfrog (Feb 16, 2006)

> if I use a single 1/4" ID bulkhead for drainage in multiple 20/10 verts, and if each single 1/4" tube drain goes to a 3/8 main drain,


vanillagorilla,

I have a 3/8" drain on one of my first vivs and it really sucks!!! When I drain the viv with a valve, it just drips and takes hours to drain off half of a gallon of water. Since that viv, I always put in 1/2" drains and valves. If 3/8 is slow, your 1/4" would be worse. I know it sounds like it is easier to have a smaller hole, but it is not.

And Mike, thanks for your suggestion on these electrical connections. I have always been using the plumbing connections (water=plumbing) and they are ok, except you cannot find the "nut" to put on the inside. I am in the process of making 6 more vivs and I will be putting your connectors in all of them, they are SO much easier. Who would think water and electricity mix except an engineer!!! :lol: :lol:


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## defaced (May 23, 2005)

You're more than welcome Steve. And don't give me too much credit, I got the info needed to find this part from someone else: electrical PVC uses non-tapered pipe thread. Without knowing that, I would have never looked in the electrical section for this stuff.


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