Bean Animal with only one hole drilled

[makutaku]

Initially I was trying to design a built-in overflow that is both silent and almost invisible.

The fact that I do not want to paint the back glass, it makes the second requirement very hard to be achieved.

Several people here in this forum enjoy their hang-on overflow box. Its flexibility and external design obviously help achieving a cleaner presentation. However, this benefit does come with water damage risk.

In order to mitigate this risk, I am considering the following hybrid design:

* Hang-on overflow with two stand pipes: Full Siphon + Open Channel
* Plus the drilling of one hole in the tank for the Emergency stand pipe

Of course the diameter of the hole drilled should match or surpass the other two in the hang-on box, following the BeanAnimal specs.

In my situation I would place the hang the overflow on my less visible side and drill the hole in the back.

Disadvantages (when compared to a pure hang-on approach):
* Having to drill one hole, instead of none.
* A little more clutter: bulk-head and stand pipe.

Advantages:
* As safe as a Bean Animal built-in overflow.
* No need to have any built-in overflow box and aquascape around it.
* The only stand pipe visible in the back, (emergency), would be dry, allowing someone to use clear PVC without having to deal with algae.


I am looking for your invaluable feedback before I put this plan in motion.

Cheers!

 

[shoggoth43]

I do a similar thing now as a herbie design. One pipe is flooded, the other barely flows anything if at all. It's an eshopps overflow with two pipes. The main flow does not have a standpipe in it.

It can be silent. It provides some backup in the event of a clog which has happened, dead fish. It's reasonably set and forget.

Downsides: you still have a siphon tube as a point of failure. If that gets clogged, filled with algae or air, you are going to have a mess. You will also need to tinker with levels a bit initially.

I had my emergency standpipe too high which caused problems. I figured this would cause less splashing, which it did. However, because the level in the overflow box was not significantly lower than the tank, the flow through the siphon was not very fast which meant my pump could overpower the siphon.

The siphon U tube is 1.25" so it can easily keep up with the pump otherwise. It was a level issue. If you start a siphon in a hose, you will fill up a bucket much faster if the bucket is on the floor since the water flows faster through the hose f the end is much lower than the tank. Same idea here. This is/was a common issue if you read enough of the herbie threads on the reef sites where they modified U tube type overflows.

Lower the emergency standpipe a bit lower than you think it should be and you should be fine.

I haven't needed the extra emergency overflow that bean has and you may not either but you'll need to decide for yourself. It would be easy enough to do the Herbie and add the extra overflow if you are nervous about it later on.

Other thoughts:

Consider drilling the tank. You could easily drill the tank and the overflow box and inner box and use the bulkhead to clamp them together with additional bulkhead gaskets or add the glass boxes the bean animal design uses. The siphon U tube is your biggest failure problem here, and it's really not that big a problem if you check it and clean it periodically.

Use a gate valve. A ball valve will work but won't let you dial it in perfectly the way the gate valve will. Put the valve at the BOTTOM of the pipe/tubing, just above the sump. While it will work f you put it just under the overflow bulkhead fitting it will take longer to purge the air in the line. Make sure to submerge the end of the main line slightly.

Varying water levels in the sump can throw off your adjustments. It's similar to moving the end of the hose up/down and will affect the strength of the siphon. Place the end about an inch or so into a small pitcher or jar in the sump that will then overflow into the sump itself. This gives a consistent back pressure. If you don't do this, and you leave the valve up top by the overflow, and you use a ball valve, you'll see the water level in your overflow wander quite a bit. If you use a conventional wet/dry letting the hose dip slightly below the biotower and then have it come back up to the top of the filter will do the same thing, or you can just mount the valve to the elbow fitting on top of the filter. Either way the pressure AFTER the valve will be consistent which will make for a stable level.

If you use a gate valve open it fully first. Then count your rotations required to close it down to your "perfect" settig. If you have a clog you'll need to open it fully all the way and then close it again. It's easier to dial it back in if you remember where you started from. Remember that this may change over time and can change drastically after you clean the tubing/pipes.

As you are under full siphon, IF you are low on cash and feeling adventurous, depending on your flow rates you may be able to get away with undersized tubing on your main line. Say 3/4" vs 1". Practically speaking I wouldn't do this if you're running more than 500 GPH, but it may be something you can try.

I've drilled out my overflow box. I have 1.5" fittings which run to 1" braided hose lines down to a cheap ball valve in the sump with no jar/bucket for constant pressure. I'm running at least 800 GPH with a reasonable stable level in the overflow. Mostly this is because I've made modifications to things recently and can see the wandering levels compared to when I had the other way.

 

[makutaku]

Thank you, shoggoth43, for taking the time. :encouragement:
It's a lot of material so I will just quote the parts that are not clear.
I took note of the rest, and will use your experience and adjustment tips as I build this thing.

Downsides: you still have a siphon tube as a point of failure. If that gets clogged, filled with algae or air, you are going to have a mess.

The point I wanted to make is that if you drill the tank for your (extra) emergency stand-pipe, even if your hang-on siphon U tube gets clogged or loses siphon, you will still be safe.
In that case you would be upgrading your relatively unsafe hang-on Herbie, to a safe hybrid BeanAnimal.

Alternatively, people who own one-pipe hang-on overflow, by drilling just one hole in their tank, they would upgrade to a hybrid Herbie style, and be safer than yours.

I haven't needed the extra emergency overflow.

And I hope you never do. :friendly_wink:
The key, for me, though, is not about having an extra emergency overflow (Herbie vs BeanAnimal), but having at least one emergency pipe built/drilled in the tank. For example: a hybrid Herbie as I described above is much safer than a Bean Animal hang-on overflow (even if such a thing existed).

You could easily drill the tank and the overflow box and inner box and use the bulkhead to clamp them together with additional bulkhead gaskets or add the glass boxes the bean animal design uses. The siphon U tube is your biggest failure problem here, and it's really not that big a problem if you check it and clean it periodically.

What I am proposing just requires one hole drilled in the tank for an emergency stand-pipe. No need to drill overflow box and inner box.

 

[shoggoth43]

I missed the part about drilling the TANK and thought you were drilling the outside overflow box for another outlet.

Still, if you are already drilling the tank, why not simply upsize the hole? Drill the overflow boxes to accept the larger bulkhead fitting as a clamp for them all with the extra gaskets?

The larger hole makes it far less likely to ever clog or be blocked and you completely remove the U tube as a possible issue. If you are thinking 1" lines go with a 1.5" bulkhead. Any fish that would block that would block the 1" lines. You could also put on a 1.5" strainer, or just create a gutter guard cover for your overflow.

Everything else for a herbie style would remain on the outside and you could drill a third outlet in the outer box if you really felt the need.

-
S

 

[makutaku]

Thanks shoggoth43 ! I understand what you were saying now. Your idea is different, but very worth considering.

Advantages I see in your approach:
* It retires the U tube even during normal operation.
* The hole drilled in tank would be covered/used by the hang-on overflow, so less visible clutter.

Disadvantages I see in your approach:
* More complex to implement since it requires aligning the hole drilled in the tank, with holes drilled in internal and external box.
* I can order the tank with one hole already drilled, but I would have to drill the hang-on myself. Doable, but if I mess up the alignment these hang-on's are not cheap.
* If the hang-on is going to be placed on the side of the tank, the hole would also have to be drilled on the side of the tank, which would impact the potential resale value of the tank.
* Although making a larger hole minimizes the risk of clogging, there's only one hole, and it's in regular use. If it ever clogged it would be too late - you would get no early warning.

 

[gsjmia]

makutaku, I have a setup that is similar to what you are describing and it works fine. I have a 1 1/2 inch hole drilled for an internal overflow, but was worried about the same things you described, so while I was drilling, I drilled an extra hole for a 1/2 inch bulkhead and made it into an emergency overflow. In hindsight it should have been a little bigger but with the large primary overflow I didn't think that would ever clog 100%.

Here it is from the outside:

[attachment=1392:name]

And from the top:

[attachment=1393:name]

 

[shoggoth43]

Well, your approach allows for a second pathway. You don't specifically have to use a HOB overflow system with what I proposed, any box which will hold water would work once the tank is drilled. A couple of cheap acrylic boxes from Target or other would work and you could use a hole saw easily to make the holes for the standpipes and whatnot.

I guess my "issue" if you could call it that is more of a drilling question. If you are going to drill the tank, why only the one hole? If it's a concern about cost of drilling the hole then drill it larger and be done with it, at least to me anyway. Then again I don't have anything in my tank that would plug a 1.5" hole unless an angel or discus made it into the overflow, and I've probably got other issues at that point. The sword leaves would likely curl up but not block that size hole and a strainer would probably eliminate that concern.

If it's a concern about the tank that you don't want to weaken it with a second hole, why not another HOB overflow box? Then you're back to cost again though.

But again on the cost, once you drill one hole, it's not much more to drill a second or third and then you just need the internal overflow box for the bean.

Your hybrid solution is fine and I fully understand what you've come up with. I guess at this point I'm wondering why you would bother to go that route since the drilling removes many of the weaknesses of the HOB.

Around here resale value of tanks is not spectacular unless its a large tank. But even then you take a pretty big hit. Most would plate over any holes in the wrong spot on the bottom or back of the tank and they would factor this into the asking/purchase price. I think you mentioned something about the side of the tank and maybe this is where I'm losing the discussion here.

In any event, it seems as though we both agree largely on the technical details at least, if not the philosophical reasons.

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S

 

[makutaku]

makutaku, I have a setup that is similar to what you are describing and it works fine. I have a 1 1/2 inch hole drilled for an internal overflow, but was worried about the same things you described, so while I was drilling, I drilled an extra hole for a 1/2 inch bulkhead and made it into an emergency overflow.

Thanks for the pictures. I see that you also used clear PVC.
Have you tried to find a clear (or even white) bulk head ? After some online search, it seems it doesn't exist.

How big is the space between your emergency hole and your water line ?

 

[makutaku]

I guess my "issue" if you could call it that is more of a drilling question. If you are going to drill the tank, why only the one hole? If it's a concern about cost of drilling the hole then drill it larger and be done with it, at least to me anyway.

It's definitely not about the cost of drilling. When compared to the cost of the shipped 125G starfire rimless I will soon order, each hole costs peanuts! :miserable:

My main concern is aesthetics. I would like to have the back glass as clean as possible. One drilled hole with clear PVC (and no internal or external box) is the maximum I am willing to sacrifice. Otherwise I would prefer just to have a hang-on (Eshopps) on the left side (my least visible side) modified for Herbie style like you have.

Although I prefer to keep things as simple as possible, I feel that just one hole is a good compromise of safety, aesthetics and simplicity.

In any event, it seems as though we both agree largely on the technical details at least, if not the philosophical reasons.
S

Definitely! And thanks again for sharing your idea!

 

[shoggoth43]

Sounds good. My aesthetics will have me painting the back of the tank black with a slimline glass overflow most likely to cut down on the shading effect of the box.

I also have to eliminate the U tube as an issue as the last time I had a friend take care of things he somehow managed to knock it loose and killed the siphon. I'd recommend at least upsizing the one bulkhead you drill to take this kind of failure into account. The herbie/bean styles can flow a LOT more water than you think and a 1" siphon tube moves more than a 1" hole on the side of the tank due to head pressure. If that U tube fails you may end up with a flood anyway even with a bulkhead of the same size in the tank wall.

Sounds like it will be a nice tank.

-
S

 

[Gerryd]

Hi,

Can you drill on the end glass instead of the back wall?

Also, a HOB overflow always has some risk. The siphon tube can be clogged (Lifereef uses 2 for larger models btw) and the CPR siphon type need a doser pump to pull air out all the time.

I hear you on the aesthetics part but if you are willing to drill one hole, I would drill the ends and have the builder construct a nice builtin overflow and either bean or herbie it. Can run the width of the tank and can be shallow and thin as well. Like a coast to coast but on the end not the back This will provide some nice skimming and also be quiet and safe as can be. I would perhaps drill 2 x 3/4 bh for your main and normal overflow, and perhaps a 1" for the emergency if space is an issue. 1" are best though esp for your size tank.

Drilling it this way is the safest IMO but I use the CPR HOB model. I have it herbied and is dead quiet. I check the dosing pump daily and have spares.

I have a lifereef but like the dims of the CPR a bit better as the footprint is smaller...

 

[makutaku]

I'd recommend at least upsizing the one bulkhead you drill to take this kind of failure into account. The herbie/bean styles can flow a LOT more water than you think and a 1" siphon tube moves more than a 1" hole on the side of the tank due to head pressure. If that U tube fails you may end up with a flood anyway even with a bulkhead of the same size in the tank wall.

This is something important and I think I will up-size the emergency pipe to at least 1 1/4 ". When it's set up, I will also test to make sure that if siphon is lost, the emergency can handle all the flow.

Besides space, the trade-off of a larger hole is again aesthetics, specially because I can't find a BH that is not black. Maybe if the hole is lower it will be easier to hide it. Actually, if I position the hole correctly, and make it larger, I will have the option to try your approach eventually.

 

[shoggoth43]

I'm not sure where you are, but flexpvc.com has bulkheads in 1.5" and 2" in white and possibly some in gray. That may be a possibility.

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S

 

[makutaku]

Can you drill on the end glass instead of the back wall?

Yes, I could, but if I move to another house one day, I will also take the tank, and the viewing side may change.

... I would drill the ends and have the builder construct a nice builtin overflow and either bean or herbie it. Can run the width of the tank and can be shallow and thin as well.

I don't have many options here in the northwest. The place I am ordering doesn't customize overflow too much. That's why I already bought an Eshopps 1200.

I am now figuring out how many holes, if any, I want them to drill before they ship the tank to me. I am thinking at least one for emergency, probably for 1.5" pipe, and probably on the back-left, but don't know how low to drill it from water level.

I am also wondering how ugly would be another hole (3/4") on the back right corner for the return, as opposed to just return over the top.

 

[makutaku]

I'm not sure where you are, but flexpvc.com has bulkheads in 1.5" and 2" in white and possibly some in gray. That may be a possibility.

I had them in my list, so I don't know how I missed it!
Thanks a lot!

 

[shoggoth43]

I would think putting the bottom of the bulkhead flange at the 4-6" mark down from the waterline would make the most sense. This way, if you ever decide to put and overflow box over/around it you won't need an overly large one. At the same time, you won't have too much pipe showing in the tank.

I'm not sure on the returns. I run mine over the top. Most of mine T from 3/4 down to two 1/2 inch loclines. As I often have emergent or floating plants I just "tune out" the returns as tree roots or branches over the rim since they aren't overly large. 1" loclines may not mentally disappear so easily. Depending on your scaping this may not really work for you.

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S

 

[Gilles]

Remember that clear PVC will become 'ugly' over time due to algae etc..

 

[makutaku]

Remember that clear PVC will become 'ugly' over time due to algae etc..

It shouldn't get ugly so fast in this case since it won't be carrying any water. An emergency pipe should only get algae on the outside, which would be easier to clean.

 

[shoggoth43]

Depending on the tubing/pipe you may just be able to friction fit it and easily replace it if it gets too dirty as another option.

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S

 

[makutaku]

I would think putting the bottom of the bulkhead flange at the 4-6" mark down from the waterline would make the most sense. This way, if you ever decide to put and overflow box over/around it you won't need an overly large one. At the same time, you won't have too much pipe showing in the tank.

Do you know approximately what's the minimum space between tank and wall if the back glass is drilled for a 1.5" pipe?

I'm about to order my tank, so I need to decide on this since it will be drilled by the builder. My order of preference in terms of diameter is 1.5", then 1.25" then 1", as long I am not forced to place tank 4" or more from wall.