Nano-Reef.com Forums > Overflow Diagrams

Tigahboy

Oct 14 2005, 10:17 AM

Just finished the 3 I'm most familiar w/ (i.e. have made/used for my own tanks).

hope it helps...

I'll try to do a breakdown of pros and cons of each overflow type as well. After I rest a lil tho.

EDIT - I am adding a diagram for the Herbie overflow since wombat was so kind enough to contribute them to this thread.

Herbie Overflow
Diagrams courtesy of Matt Wandell (wombat)

You may add either a strainer at the top of the standpipes or an elbow. I've seen both. Some even add a durso for the higher (secondary) standpipe. But the main elements of a Herbie include a lower, primary standpipe with a gate valve to control the water level in the overflow box and a higher, secondary standpipe.

There are discussions about the Herbie throughout this thread, please do a search for them within this thread for more information.

reef n ale

Oct 14 2005, 10:51 AM

I'll be following this one Tigah! Thanks!!

Rob

crizq0

Oct 14 2005, 04:58 PM

*bookmarked*

Thanks Tigah for the very useful information. Great diagrams.

Tigahboy

Oct 14 2005, 05:10 PM

QUOTE(crizq0 @ Oct 14 2005, 02:58 PM)

*bookmarked*

Thanks Tigah for the very useful information. Great diagrams.

no problemo. just doin my "job." =) haha.

will post more info about each sometime next week.

and if y'all have any questions or diagrams need clarification, lmk.

nanocustoms.com

Oct 14 2005, 05:27 PM

Tigahboy = Reef Pimp of the Southwestern World!!!

Thanks Dennis

Chris

Cesar

Oct 14 2005, 05:44 PM

Your're the man Tigahboy.

gjones

Oct 14 2005, 07:33 PM

Thanks for the diagrams Tigahboy!

Sebea

Oct 14 2005, 07:39 PM

Which one would you suggest, the durso, or the stockman, for an internal overflow?

Thanks for taking time to put the diagrams together.

Tigahboy

Oct 14 2005, 07:54 PM

QUOTE(Sebea @ Oct 14 2005, 05:39 PM)

Which one would you suggest, the durso, or the stockman, for an internal overflow?

Thanks for taking time to put the diagrams together.

Stockman. I'll elaborate more when I do the pros and cons chart for each.

Daemonfly

Oct 16 2005, 05:21 AM

Good thread. Might want to add in the links to the designers' sites too.

http://www.dursostandpipes.com/

(Stockman dfesign is also available on the durso site under "popular modifications")

Tigahboy

Oct 16 2005, 05:37 AM

good call.

but I'm not sure who designed the other 2.

EtOH_is_good

Oct 16 2005, 10:47 AM

gawd! another thread for the lazy. lol

tigah, can you build me an award winning pico entry.

calvin

Oct 16 2005, 06:54 PM

thanks for this, Tigah. I have a question:

I recently bought a used Oceanic 40g from an LFS that was going out of business. It came pre-drilled with a 1" bulkhead w/strainer near the top right and a 1/2" return near the top left. Do you think

1) I should use the "external durso overflow" setup? Will this provide higher gph than just a regular drain (i.e. no durso)?

2) Will one 1/2" return provide enough flow for softies & LPS? I have no interest in keeping SPS. I think I may put a "Y" on the return with some locline attached.

calvin

Oct 17 2005, 02:44 PM

bump

EtOH_is_good

Oct 17 2005, 06:05 PM

gawd. the return will generate a lot of pressure. what kind of flow do you want in the tank. for a target of 15-20x turnover, i would want at least 3/4. lots of pumps have 3/4 outs and easier to reduce the pressure.

calvin

Oct 17 2005, 06:17 PM

yeah, I think 15-20x turnover would be good. so are you saying you would try to increase the return size to 3/4"?

EtOH_is_good

Oct 17 2005, 06:22 PM

3/4 will give you more pump options to get that kind of turnover. a stand pipe won't increase your flow. flow capacity is limited by the size and the depth of the hole(s) of the standpipe to the water level.

Tigahboy

Oct 17 2005, 06:24 PM

QUOTE(calvin @ Oct 16 2005, 04:54 PM)

thanks for this, Tigah. I have a question:

I recently bought a used Oceanic 40g from an LFS that was going out of business. It came pre-drilled with a 1" bulkhead w/strainer near the top right and a 1/2" return near the top left. Do you think

1) I should use the "external durso overflow" setup? Will this provide higher gph than just a regular drain (i.e. no durso)?

2) Will one 1/2" return provide enough flow for softies & LPS? I have no interest in keeping SPS. I think I may put a "Y" on the return with some locline attached.

External durso will not give you higher flow thru. But just a simple bulkhead at the back will be very noisy and the flow thru won't be constant (i.e. siphoning faster and slower).

two 1/2" returns would be more ideal.

seis66

Oct 19 2005, 02:13 PM

QUOTE(Tigahboy @ Oct 17 2005, 06:24 PM)

External durso will not give you higher flow thru. But just a simple bulkhead at the back will be very noisy and the flow thru won't be constant (i.e. siphoning faster and slower).

two 1/2" returns would be more ideal.

There's a post written by wetworx about flow rates depending not just the size, but the position in the back wall of the tank. Briefly, it says that the closer the hole to the top of the tank, the slower the flow rate will be. So yeah, it wont be as fast, but that doesn't mean that'll be turtle-speed flow rate. A part of the wetworx post as follows

QUOTE

Yep. The calculations I did come up with that figure, now keep in mind that my calculations are based on a vertical hole which technically wont drain as much as a horizontally mounted hole (simple example: a 1" hole at 1/2" depth mounted verticaly would only be half underwater yet a 1" horizontal/flat hole under even 1/4" water would be completely covered). So if you were to put a hole on the bottom side of a tank, as long as it is vertical, it will have slightly less pressure on it than a bulkhead mounted on the bottom glass because of it's height. So a bottom hole will have a slight flow gain on a side hole, but I am not going to redo my calculations because were talking a minimal gain here, considering we would be at 12" or more of depth the flow on a horizontal bulkhead is already in the hundreds. More flow can be lost with screens over the bulkheads and accumulation of crud on a bulkhead's intake, easily over 20%. That's why I would never go with a bulkhead less than 1" unless we are using it for less than 100gph, or you are sure to prefilter the water enough to prevent clogging (D, I think you will be fine as long as you put a sponge or screen in your overflow above the bulkhead to keep any chunks away).
Just short of graphing the chart with line curves I have for flow by cross referencing hole diameter with hole depth, I can post the following:
1"bulkhead @ 1" depth=338.6gph
1"bulkhead @ 1.5" depth= 414.8gph
1"bulkhead@ 2" depth=478gph
1"bulkhead@ 3" depth=586gph
1"bulkhead@ 4" depth=677gph
1"bulkhead@ 5" depth=757gph
...if you even need to know what the possible flow for a hole at a given depth is for more flow you dont have a nano anymore, and you are in the wrong forum.
3/4"bulkhead@ 1"depth=190.5gph
3/4"bulkhead@ 1.5"depth=233.3gph
3/4"bulkhead@ 2"depth=269gph
3/4"bulkhead@3"depth=329gph
3/4"bulkhead@4"depth=381gph
...you can draw the rest of the curve from there.
1.5"bulkhead, I dont think anyone needs these on a nano because 1" is enough for most tanks up to 40 gallons, and remember...a 1.5" bulkhead has more than double the intake area of a 1"...so were @ 933gph at just 1.5"deep.

Cheers

calvin

Oct 20 2005, 06:29 PM

thanks. I remember reading this a long time ago but I forgot about it

GruntSculpin

Oct 23 2005, 09:12 PM

How do you plan where to drill the holes for an external Durso setup? I've seen you do that in rbaby's tank and your 15s and was planning on emulating when my 33 arrives.

Chris

Opcn

Oct 25 2005, 09:06 PM

it seems to me that the externa durso should have some sort of a downward facing elbow on it or something so that the ater always forms a sealwith the mouth of the overflow.

neanderthalman

Oct 26 2005, 08:25 AM

If you use a strainer basket, like in the drawing, it will skim the surface. With the external durso, you don't have an internal overflow box to do that skimming, so you compromise.

Opcn

Oct 26 2005, 10:23 AM

If your skimming then air is coming in and the hole in the top making the overflow a durso overflow doesnt do much does it. The hole keeps a full siphon from ever forming but that hapens when skimming too doesnt it.

neanderthalman

Oct 26 2005, 10:56 AM

My understanding is that the hole isn't a siphon break, it's purpose is to disrupt the vortices that form around oveflows. It's a shut the hell up hole, 'cause without it, the overflow will be very noisy.

Opcn

Oct 27 2005, 10:10 AM

well, the vortext forms because of the siphon effect from the column of water in the pipe, then when the level gets low enought it makes a toilet like noise because the column of water falling pulls in air along with the water.

neanderthalman

Oct 27 2005, 10:43 AM

That's correct.

The hole in the top of the durso somehow reduces the flow rate. The reduced flow rate means that less or no air is sucked into the intake - no noise.

Blind Tree Frog

Nov 3 2005, 04:51 PM

So back to the advantage of the stockholm over the durso

Opcn

Nov 3 2005, 07:46 PM

Takes up less space, harder to clog?

Tigahboy

Nov 5 2005, 03:32 AM

QUOTE(Opcn @ Nov 3 2005, 04:46 PM)

Takes up less space, harder to clog?

That pretty much sums it up. =)

lgreen

Nov 5 2005, 04:09 AM

Holy Crap! Great Thread Tigah!

I really like that you explained some of the noise issues. It would be awesome if you extended your discussion into how to make it quiet at the other end from your experience.

doody

Nov 9 2005, 06:43 PM

How the heck do I subscribe to this thread with out posting on it?

GruntSculpin

Nov 11 2005, 01:44 PM

With a full-height internal overflow box and a standpipe, does the stagnent water at the bottom of the box ever pose an issue?

Chris

neanderthalman

Nov 14 2005, 06:21 PM

I don't think the water at the bottom becomes stagnant due to the flow created by the water tumbling over the wall of the box.

GruntSculpin

Nov 14 2005, 11:13 PM

QUOTE(neanderthalman @ Nov 14 2005, 11:21 PM)

I don't think the water at the bottom becomes stagnant due to the flow created by the water tumbling over the wall of the box.

I ended up making a Stockman for my 33 as I only had 3x5" to play with. I thought I was being really clever at the hardware store, but its exactly like in Tigah's diagram. I made another clever decision by not gluing the standpipe in during testing, but that was a disaster, as the entire overflow box emptied into the sump once power was cut. BUt hey, that's what testing in the garage is for. Pipe is glued in and I'm rearing to go.

Chris

Tigahboy

Dec 8 2005, 08:58 AM

you mean gluing the standpipe to the bulkhead? weird, I've never glued any of the parts for a inside tank stockman or durso standpipe. no problems.

tootsiedaisy

Dec 8 2005, 08:13 PM

tigah you rock, Now please help me , I have a 1" bulkhead I built a small overflow box that attaches to the bulkhead,Then it an exact copy of your external Durso design below the T there is 1" PVC straight down then 45's to side of sump and then 45's again to go back straight down to sump,In my sump I have a 4'' pvc pipe glued to the bottom of sump were pipe dumps, My problem is its sipioning and splashing in my 4'' pipe, I stuck some old tubing down the top of durso cap but the pipe will shake and the splash any suggestions. Thanks

Tigahboy

Dec 9 2005, 06:59 AM

try making the hole in the endcap (top of the external durso) a little larger (no need for the tubing). that might help reduce the siphoning/rush of water.

GruntSculpin

Dec 9 2005, 11:53 AM

QUOTE(Tigahboy @ Dec 8 2005, 01:58 PM)

you mean gluing the standpipe to the bulkhead? weird, I've never glued any of the parts for a inside tank stockman or durso standpipe. no problems.

Exactly. The bulkhead fit very loosely, more than any of the other PVC joints, and just wouldn't seal. I had hoped to not make it permenant so I could try different standpipe options if I ever needed to.

Chris

Tigahboy

Dec 9 2005, 11:57 AM

maybe the bulkhead was defective. I've never had to glue any of the standpipes to the bulkhead.

maybe you could've glued a coupling to the bulkhead and then leave the standpipe end of the coupling unglued so u could switch out standpipes.

ZooGirl

Dec 9 2005, 01:47 PM

Tigah, is your 15s noisy? On that tank you have an external durso correct? I was thinking of doing that on my 20L but it will be in my bedroom and I want to be able to sleep at night.

Tigahboy

Dec 9 2005, 03:58 PM

I think no matter what, there will be some noise (i.e. sound of flowing water).

My 15g is in my bedroom as well. like 2-3 feet away from my bed. but I'm a deep sleeper so I guess it doesn't bother me as much. If you are a light sleeper, maybe it might not be the best for a bedroom set-up.

Sebea

Dec 9 2005, 04:07 PM

Dennis,
For an external overflow, is the best way to reduce noise to put a stockman in the external box?

Tigahboy

Dec 9 2005, 04:09 PM

Yeah, I think stockman's are the best bet. But others say durso's are just as quiet.

Sebea

Dec 9 2005, 04:10 PM

Great, thanks.

steelhealr

Dec 9 2005, 05:01 PM

Tigahboy...added your thread to the DIY library. SH

Sebea

Dec 10 2005, 05:09 PM

I have one more question, for a pico with an external overflow, would 4" height be enough for a stockman?

Tigahboy

Dec 12 2005, 02:53 PM

I think 4" should be fine. but it depends what size stockman u plan on utilizing. and u might have to use a dremel/saw and cut the coupling a little to shorten it...but that won't really affect it's efficiency.

is this an external overflow box like reefnale's or is this a HOB type overflow?

Sebea

Dec 12 2005, 03:03 PM

It will be an external like reefnale's, but for an 11" cube. I think the overflow box dimensions will be 4" long, by 4" tall, by 3" wide. I only expect at maximum, 300 GPH for the return pump.

Tigahboy

Dec 12 2005, 03:06 PM

eh. you'll be fine then.