Overflow Diagrams

[Mirepa]

So I got a durso setup in my 40b with the bottom drilled out for the bulk head.

 

I'm running one of those drain hoses (vacuum hose) from the bulkhead into my fuge.

 

I can't help but notice there is still a annoying gurgle (not as bad) and a ton of micro bubbles.

 

 

 

Any suggestions on cutting down on the noise and bubbles? More so the micro bubbles as they are really messing with the clarity in my display.

 

Thanks!

[Tigahboy]

Try making vent hole bigger. May help with both.

[Lawnman]

Try this pull the upside down u shaped pipe off the durso it is 2 90 elbows together. Run a hose down the drain pipe into the sump no more gurggling noise just a little air noise being sucked down.

[ajmckay]

So I'm in the process of designing an overflow for a 40br plumbed to a 30br, then plumbed to a 29g sump. I'm interested in using an overflow which drains out the back.

 

Do you think it would be possible to "herbie" it to keep it quiet? I would need to do it twice actually...

 

Next, what do you think about inside elbow orientation? Up? Down? No elbow?

 

And finally, what about overflow bulkhead size? Does the backup drain need to be smaller?

 

See my diagram and tell me what you think.

[Tigahboy]

Yes, that should work. I would just make sure the lower drain with gate valve is low enough so that it won't suck in any of the air from the surface. Maybe at least 3" from the intended water level in the sump to be safe.

 

For the primary drain, yes, I don't think it matters whether you have the elbow up, down, or no elbow at all.

 

The back-up drain is the same in mine (both 1"). But it doesn't have to be.

 

 

 

I'm pretty new to the herbie tho, so others should chime in.

[ajmckay]

Okay, so I've been going over this overflow in my head for the past few days and I think I've got the optimal design figured out.

 

I'm thinking that this internal overflow box will be about 7.5" tall x 10" long x 2" thick.

 

I've decided to use elbows to make the difference between the intakes as far apart as possible to minimize the possibility of air getting into the primary intake. The secondary intake will be about 1/2" below the teeth on the overflow. I plan on making this out of 1/4" glass (probably overkill, but I have some lying around), painted black on the inside, with acrylic or glass teeth.

 

Here are my questions/concerns I would like some input on:

1) I would like somewhere between 500-700gph of flow. What size bulkheads do you think I should use? Right now I have 1.5" for the primary, and 1" for the secondary. Do you think I could maintain the same flow (taking advantage of the herbie method) with 2 1" bulkheads?

 

2) To keep the size minimal, I decided to use elbows, which keeps the 2 holes for the bulkheads about even. Would there be a problem with the 2 holes being even do you think? I can't really think of any, but I have no experience with overflows.

 

3) With regard to drilling the glass, does anyone think the spacing of the holes is too tight/not tight enough? I don't want anything to crack!

 

Thanks for your input!

 

Edited September 1, 2009 by ajmckay

[Tigahboy]

Make sure the overflow box is big enough so you have enough clearance to move the elbows in and out of the bulkhead. 2" doesn't seem like enough clearance. I'd actually get the elbows in hand and see how much you need to move it in and out.

 

Or better yet, since it seems that you will be adding the overflow box yourself, might as well try out the herbie without the overflow box first and see how much space you will need and such to get it working properly, then add the overflow box.

 

1) I have an eheim 1262, and get around 500-700 gph thru my 1" drain no prob. So using two 1" should be fine.

 

2) There shouldn't be any probs with having bulkheads the same level. The elbows should accomplish what you are aiming for.

 

3) Someone else will need to chime in about the glass stuff.

[ajmckay]

Hey thanks Tigah.... Your feedback has been critical in my overflow design. As I've never had an overflow before, I'm not 100% sure of my ideas... (It's a lot to think about designing a stand, tank, sump, overflow, & frag tank at the same time, and I'm moving in 2 weeks!)

 

Anyways, I think I agree that a 2" thick overflow might not be quite enough to place/remove the elbows. I just had the idea though of cutting off some of the elbow (the part that would stick into the bulkhead) since I think I only need 1/4" or so as long as I keep a tight fit and maybe use just a dab of silicone or something to keep everything in place and keep from air getting in. If I trim this back I think 2"-3" is more doable.

 

I also agree about the 2 1" drains... I'm thinking I will be fine with the 1" drains, but I'm still not 100% sure... I want a degree of future adjustability built in. As I understand it, the whole point of the herbie is that you can restrict the flow through the main overflow enough to make it completely silent, yet still maintain enough flow through it that you don't have a lot of water using the secondary drain either. I don't want to have an undersized drain such that the secondary drain would be in use all the time... So as of now I think I would be better off going with a 1.5" for the primary and a 1" for the secondary. I will still keep the holes horizontally even though and use the elbows to give the desired effect. I'm all for maximizing display area.

 

To help others determine bulkhead sizing, Wetwebmedia has an interesting experiment with regard to bulkhead sizing and it opens your eyes to how easily the flow can be restricted. They definitely suggest "go big".

http://www.wetwebmedia.com/BulkheadFloRateArt.htm.

 

I also like your idea tigah of putting everything together first. I think I'll goto my LFS and get the dimensions of some bulkheads (and probably just buy the PVC elbows), and then fashion everything out of cardboard or something just to visualize it.

 

I'll keep everyone updated on my overflow design.

[Tigahboy]

Awesome link for flow rates. The herbie should be siphoning, so you'll get pretty good flow rates thru the bulkhead.

 

I also bought the bulkheads and pvc elbows to see how much space I would need in my overflow box in my planning stages. Yes, you can also cut the elbows to make it shorter. I don't think you'll need silicone tho.

[ajmckay]

Okay, so I designed my overflow and made a "model" out of cardboard.

 

The final dimensions are 8.5" wide, 6" tall and 3" deep. I think that sounds pretty good.. I'll use a 1.5" bulkhead for the main drain with a down facing elbow. The secondary drain will be a 1" drain with an upward facing elbow.

 

See the pics below.

 

 

 

 

 

The major thing I'm noticing is how smaller the 1" is than the 1.5".... But I guess that's how it is.

 

How does it look in cardboard? I think it'll look much better in glass (with acrylic teeth).

 

The only modification I think I'll need to make is making the teeth a little shorter. Right now I have them 1" long so if I keep the water level 1/2" below the teeth then I think that's a little low.

Edited September 4, 2009 by ajmckay

[Tigahboy]

VERY nice, man. I like your thoroughness in the planning stage.

 

I'm going to make one more pitch for 2 x1" drains. Haha. The difference in size is HUGE, and you'll have to also think about how heavy all that 1.5" PVC pipe will be hanging from the back of your glass tank (again, I'm no expert on glass so maybe it's no big deal)... or even 3 x 1" drains like this guy: http://www.reefcentral.com/forums/showthre...hreadid=1310585. The only difference is he has 1 secondary drain to drain a small percentage of the flow into the sump and 1 more secondary drain to serve as an additional back-up just in case.

 

With regard to teeth, I think you should make sure you have teeth on all 3 sides of the overflow box. Also, it's safe to assume the water level in your tank will be about 0.25" ABOVE the bottom of the teeth, so 1" teeth means the water level will be at the most 0.75" from the top of the tank rim (possibly less if if you have tons of flow going thru the overflow box). Does that make sense?

 

If you add a vortech and get some wave action, you want to make sure 0.75" is enough. It likely will be tho.

 

FINALLY (and this is important), you want to make sure your overflow box is large enough to allow for the flow thru you are trying to achieve. More specifically, if you go to reefcentral (i know, i know) and use their drain/overflow size calculator, to accomplish 700gph, you need 11" linear overflow distance. And I THINK that calculation is based on an overflow WITHOUT teeth (the teeth will effectively reduce your linear distance thus reduction in flow thru as well). Right now you only have about 16.5" linear overflow distance, and if you add teeth, that'll reduce it down to some number possibly less than 11". Just something to consider.

 

Also, you don't really need that much flow going into the sump anyway (especially since they have vortechs, other small profile powerheads available on the market). You could even do a closed loop.

 

How big is your tank? Maybe 4x volume flow thru sump should be sufficient.

[ajmckay]

Thanks again for the info Tigah.

 

The tank(s) will have a total volume of 70 gallons. There will actually be 2 tanks on top of each other plumbed together. The top display tank will be a 40br and the bottom tank will be a 30br. The sump will be a 29g. The setup is very similar to evilc66's (actually I got the tanks from him - with broken back panes). I'm trying not to do this exactly like his tank though, and follow my own designs/ideas. The results will be similar, but I think mine will be better (Yeah right, when pigs fly...).

 

Anyways, here's my crappy sketch up model of the stand (Don't laugh too hard, it's my first sketch up model).

http://sketchup.google.com/3dwarehouse/det...5f313ea877362c6

 

So anyways, I'm going to think a little more about how I want to construct this overflow. I'm going to make it from 1/4" glass spray painted black on the inside. I'm not going to make the teeth out of glass, so that will have to be some sort of add-on acrylic or maybe just some gutter guard (easy solution for increased flow)? I also found out a have another week or 2 before I can get this done due to a temporary decrease in available funds. I think I'll make another model tonight experimenting with a design that is narrower but taller (If I were to ditch the elbows).

[Tigahboy]

Yeah, I use gutter guard too. Definitely maximizes the flow through the overflow box. I use magnets to hold mine up, tho some silicone theirs. The magnets are super nimbles from CJerome.

 

 

 

 

More time the better in terms of planning. Always takes me forever to get my plans down.

 

Nice draw-up! Sounds like a good project.

[Seiryoku]

I used the herbie method along with an external overflow box. Learned a few things along the way, the next tank with this setup will be a little different. The overflow cut into the back of the tank needs to be nearly the entire length of the tank. That would also allow the box to be much shallower, which would reduce the overflow noise I'm currently dealing with...

 

Tubing runs from the bulkheads directly into the sump with a ball valve on the two main drains.

 

Back of the tank.

 

Bottom of the external box.

 

Box attached to back of tank.

 

Overflow in action.

 

Messy sump with a couple of design flaws...

Edited September 4, 2009 by Seiryoku

[bitts]

here's an interesting web site cant rember who posted it origanaly though.

 

http://www.grow.arizona.edu/Grow--GrowReso...?ResourceId=188

[Tigahboy]

Great link!

[bitts]

finally got both pic and internet.

thus pics of my drain.

[wombat]

Okay, so I designed my overflow and made a "model" out of cardboard.

 

I hope you haven't already cut it!

 

I think the 1.5" bulkhead is overkill. A 1" drain will work fine, and a 1/2" emergency overflow will be enough too. Nothing wrong with overdoing your plumbing, but at a certain point you're putting a lot of weight/strain on your tank.

 

The reason I posted is that you don't need to use elbows to accomplish what you are trying to do, and you'll be able to make the box much smaller. Are they threaded or slip bulkheads on the interior side? You can use a threaded or slip plug and cut it with a jigsaw instead of an elbow. Imagine cutting through the middle of this piece left to right:

You can also save space by using a street elbow, which comes in threaded or slip versions:

 

Hope this helps.

[nanoreefnate]

hey matt! open up some space in you inbox! this is Nate... you know the guy that wanted donate coral? i have a pm waiting to be sent to you! or you can pm me.

[ajmckay]

Hey wombat.... Thanks for your thoughts.

 

Actually I have not cut yet... Actually I still haven't finished the stand! I plan on doing everything next week (taking a week off to move - starting this Saturday!).

 

I haven't purchased bulkheads... Which do you think I should go with? Also, I'm not sure exactly how the plug fits into the schematic... Could you expand on that?

 

I think I'm starting to lean towards not using the elbows and going for a thinner overflow box. It might have to be a little taller than the 6" I was diagramming, but probably not much more.

 

Also, Bitts, thanks for the pics! They're nice & clear... What size drains do you have?

[bitts]

1" bulk into 1" pvc feeding 3/4" soft plumbing, with ball valve on both lines. back up drain is set wide open, primary is restricted to about 380 gph acording to the math. size of hole vs hight of water line.

[wombat]

Hey wombat.... Thanks for your thoughts.

 

Actually I have not cut yet... Actually I still haven't finished the stand! I plan on doing everything next week (taking a week off to move - starting this Saturday!).

 

I haven't purchased bulkheads... Which do you think I should go with? Also, I'm not sure exactly how the plug fits into the schematic... Could you expand on that?

 

 

Sure, check the diagram below. If you buy a plug like this one (threaded or slip, whichever one your bulkhead happens to be):

 

 

Look at it from above and just cut straight down with a hacksaw or chopsaw like you're cutting a pie (the red line is the cut). The plug will still fit/thread into the bulkhead hole but will now functionally act like your elbow, but with a much smaller front to back profile. Hope this helps.

[wombat]

Oh, and for your size tank (40g right?) with a tank turnover of 4-6 times per hour (even 10 times per hour) you will be fine with a 1" main drain and a 1/2" emergency drain.

 

Hope this helps.

[bitts]

Sure, check the diagram below. If you buy a plug like this one (threaded or slip, whichever one your bulkhead happens to be):

 

 

Look at it from above and just cut straight down with a hacksaw or chopsaw like you're cutting a pie (the red line is the cut). The plug will still fit/thread into the bulkhead hole but will now functionally act like your elbow, but with a much smaller front to back profile. Hope this helps.

 

 

 

 

keep in mind, that this while being very cool and down right ingenius, dorps the drain size to how ever large the new opening is. which may be to restrictive. may work better to just swiss chese with drill.

[ajmckay]

keep in mind, that this while being very cool and down right ingenius, dorps the drain size to how ever large the new opening is. which may be to restrictive. may work better to just swiss chese with drill.

 

Good point.... I definitely like the idea though... cuts down on elbow room (pun intended).

 

For now I'm holding off on the tanks. I'm concentrating on building the stand, which will give me some time to really sit and contemplate the effectiveness of different overflow designs. I'll be sure to build models of each design (maybe buy some cheap PVC parts too) as I'm a visual person. I want to really maximize the space in this tank and keep it relatively un-cluttered.