Overflow/Drain Design Validation

Pillgrimm · 02/10/2012, 11:50 AM

First of all, I'd like to say Hello to everyone. I've been lurking in these forums for many moons, but haven't joined until just today. It feels like a great community, and I've absorbed a wealth of information, and am lookoing forward to being an active participant as I learn my way around the reef keepng realms.

I started a project several months back where I'll end up with a through wall tank. 72x24x30 were my original plans. I've done most of the framing, and the stand work already, and will be finishing and trimming as I get the tank in and plumbed. I was in the process of having the tank custom ordered, and pre-drilled with internal overflows on the short ends, and bulkheads in the bottom. Right as I was preparing to pull the trigger on that order, I did some ebay and cragslist scanning and found a terrific deal on a 180-ish (72x24x24). For 100$ I couldnt pass it up. It's not drilled anywhere, and is standard trim braced all around. So this brings me to my dilemma...

I've read dozens and dozens of posts reharding HoB vs internal, etc, and I've decided that it's worth the risk to drill it out and run internal overflows. Worst case, I'm out the 100$, plus the 20-ish for the hole saw, and back to the custom order scenario, with a bunch of glass to dispose of :-/ . I won't be drilling the bottom, as it's tempered, so I'll be coming in the short sides near the top. This means I'll have to reframe some of the bookshelf work on either side of the stand, but...meh, not the end of the world.

After lots of reading in these forums, I've decided I'm enamored of the overflow and drain designs in the BeanAnimal Silent Overflow threads. So here's where my concerns come in:

With the 180, and a full reef setup, I understand I should be shooting for somewhere near 3000-3200 gph of flow through the tank. Because of the through-wall design, I have to do the overflows and drains on the short ends. I like the calfo(?) edge to edge overflow, and as I mentioned, I like the 3 drain silent + failover designs in the threads I referenced, so my plan is to replicate that setup with one overflow on each short end, spanning the whole 24 inches, with around a 6"x6" internal box, and three 1.75" holes for 1" bulkheads drilled into the sides. This should, if I've understood the math correctly, allow me to handle up to 4000 gph. Again, that's assuming I've got the fundamentals down, which admittedly is a big assumption. My biggest question is, is this overkill? Am I crossing a risk/return threshold with the 6 holes? At the very least, I've almost convinced myself that I don't need TWO of the emergency drains, so maybe only 5 holes is required. One side with a full siphon, open siphon and emer drain, and one side with just a full and open siphon.

I would love to hear some thoughts on this scenario. Any guidance or advice would be appreciated.

I'm also more than willing to re-post on those threads regarding overflow specifics, but was trying to honor the "new guy" posting recomendations.

Thanks

redfishblewfish · 02/10/2012, 01:43 PM

I'm not sure where you got your turnover numbers from, but I've always used 6-10 times the DT volume per hour. So if you have a 180 gallon DT, you are looking at 1080 to 1800 gph.

I've seen the post about the Beananimal, and it looks interesting, and has gotten very positive feedback. However, you need to be a DIY'er to put those things together. I really like Glass-Holes kits...and it includes the drill bit! Buy it, drill it, done! I'm extremely happy with my 1500 gph kit.

tangs_tank · 02/10/2012, 02:22 PM

I have a 180 glass DT which I purchased new by Oceanic. It was reef-ready so overflows were pre-finished. I called Oceanic and the overflows were made for 1200gph, 600 each side. That being said, I'm no expert but I took the manufacture's word and now plumbed and running great. The numbers you gave on the other hand is kinda hugh.

Playa-1 · 02/10/2012, 04:58 PM

If it were mine, I would be planning to push roughly 1000 gph turnover thru the sump and the rest of the flow in the Display would be coming from powerheads. I would be likely be aiming for 5500gph of flow in the DT from all sources combined to start and then adjusting as necessary. I would recommend keeping the drilling to a minimum.

Agu · 02/10/2012, 06:45 PM

To Reef Central

As others have pointed out you probably don't need that much flow in the DT. Also you don't want that much flow through a sump system as it could be quite loud and splash a lot creating salt creep.

When I had a 180 reef ready I only ran about 900 GPH through the sump and supplememted with powerheads. Back then powerheads like the VorTech with the power part outside the tank weren't available. With that type of powerheads you'll have redundancy, more flexibility, and still have minimal equipment visible in your tank.

I'd suggest you scale down the overflow plans and supplement flow by other means.

slenhart1018 · 02/10/2012, 07:28 PM

I am in a similar position as you. I have a 180 gallon I am setting up. I am also looking into the bean animal overflow. My first question to you is: What is going to be behind the tank? a fish room? why not just drill 3 holes for 1 1/2" bulkheads, and do a coast to coast overflow? have your returns to the dt come through the left and right sides? Or make a box on the back wall, like, shorten the coast to coast and have the return come out on either side of that? My plan is to use (3) 1 1/2" bulkheads for the overflow and (2) 1" bulkheads for the returns, although I havent figured out where I want them just yet.

As for the flow, Im not to good with that yet, but Im figuring on using a mag 9.5 and supplementing the rest with 2 koralia 1400 powerheads. Someone please correct me if im wrong.

Agu · 02/10/2012, 07:45 PM

Pillgrimm is planning a through the wall tank visible on both sides as I understand it. That's why he wants to put overflows on the ends.

slenhart1018 · 02/10/2012, 08:35 PM

Quote:

Originally Posted by Agu

Pillgrimm is planning a through the wall tank visible on both sides as I understand it. That's why he wants to put overflows on the ends.

lol..ah hah!

Pillgrimm · 02/11/2012, 07:49 AM

Thanks for the feedback from everyone so far.

My design principles on this, and most other DIY projects I attempt, has been Over engineered is better than under. This is my first reef tank, so I'm not 100% on where that principle might steer me astray yet.

I'm interested in the disparity on recomendations related to flow volume. Most of my reading on these forums, and a few others, has led me to believe that I should be shooting for 10-20x turnover per hour. I recognize that I could supplement with powerheads, and may have to based on specific flow-needy parts of the tank, but I'd much prefer to not.

With the coast to coast overflows, coupled with the 3 drain design we've referenced, almost all applications I have seen have been 40-72" in length on the overflow. The part I am struggling with, since I must put my overflows on the short ends, as it's through wall, is whether that 24" of overflow will be enough to support the turnover flow I need. I'd much rather not drill both sides, as I give Murphy's law a chance to creep in, in direct proportion to the number of holes I drill. However, I am afraid that if I do not, I will one day wish I had.

Does length of horizontal overflow impact the drain flow volume? Or is the only limiter the bulkhead and pipe size flow restrictions? Would it impact the quality of surface skimming?

Playa-1 · 02/11/2012, 08:28 AM

If you are trying to get away from powerheads then you may want to consider a closed loop circulation system that is separate from the sump.

Pillgrimm · 02/11/2012, 08:41 AM

Thanks for the advice. I think that's worth exploring. Maybe half the flow into the sump and half through a closed loop, to avoid messes and noise in the sump? In the context of my drain design, I wonder if I could simply plumb the 3 drain side as described, drilled and all, and do hang-overs on the other short end for the drain and return on the closed loop?

Pillgrimm · 02/11/2012, 08:56 AM

While I'm at it, I thought I would post some pics of the build. All the framing is complete. I'll be adding the 3/4" shelf to the top of the stand today, with 1/4" foam under the ply.

Clearly nothing is trimmed or finished, as I can't do that until I sort out the plumbing and hood design. One thing at a time...

http://s1168.photobucket.com/albums/r492/Pillgrimm/

uncleof6 · 02/11/2012, 01:32 PM

Quote:

Originally Posted by Pillgrimm

While I'm at it, I thought I would post some pics of the build. All the framing is complete. I'll be adding the 3/4" shelf to the top of the stand today, with 1/4" foam under the ply.

Clearly nothing is trimmed or finished, as I can't do that until I sort out the plumbing and hood design. One thing at a time...

http://s1168.photobucket.com/albums/r492/Pillgrimm/

What purpose do you feel the 1/4" foam under the stand top will serve? It will only make the top of the stand unstable. Not a good thing.

Pillgrimm · 02/11/2012, 03:07 PM

The foam under the stand top will give me a good stable transfer for the top surface. It will level out small imperfections and pressure spots between the ply top and the stand frame. The stand is 4x4 post and beam, so i could park a bus on it and not have stability issue, I think. I've read a lot of heated debate on the use of foam for pressure levelling, and while I wont use it under this tank, as it's trim braced, and the ply surface should give me a good platform, I do think it will add value under the top surface.

uncleof6 · 02/11/2012, 03:19 PM

Sounds like an attempt to deal with possible crook issues, which need to be dealt with by the use of a jointer, rather than a flexible layer. In terms of small imperfections, and pressure spots between the top of the stand frame and the bottom of the plywood top, there is nothing to be gained by the use of a flexible base, its use is pointless. On the other hand, uneven settling of the foam, could lead to any number of pressure issues that will be transmitted up to the tank. You want the tank sitting on a firm solid surface. And in fact with a rimmed tank, the tank does not even need to sit on a sheet of plywood, only the rim of the stand framework.

The only time small imperfections, and pressure points are of any concern, is on the TOP SIDE of the top, and with a tank that has no rim, and the bottom glass sits directly on the plywood. I think you have been reading TOO much

Rybren · 02/11/2012, 03:37 PM

Quote:

I'm interested in the disparity on recomendations related to flow volume. Most of my reading on these forums, and a few others, has led me to believe that I should be shooting for 10-20x turnover per hour. I recognize that I could supplement with powerheads, and may have to based on specific flow-needy parts of the tank, but I'd much prefer to not.

I do believe that you are confusing in-tank flow with flow through the overflow and sump system.

For in-tank flow, 10-20x (or more) is generally fine. SPS tanks tend to have more flow (up to 40x) than LPS or Sofites tanks. In-tank flow is generally achieved by using powerheads or a closed loop system.

For the overflow/sump system, you generally want significantly less flow, perhaps up to a MAXIMUM of 10x the system volume.

Pillgrimm · 02/11/2012, 03:59 PM

Quote:

Originally Posted by Rybren

I do believe that you are confusing in-tank flow with flow through the overflow and sump system.

For in-tank flow, 10-20x (or more) is generally fine. SPS tanks tend to have more flow (up to 40x) than LPS or Sofites tanks. In-tank flow is generally achieved by using powerheads or a closed loop system.

For the overflow/sump system, you generally want significantly less flow, perhaps up to a MAXIMUM of 10x the system volume.

That seems to be the concensus from the feedback I'm getting. I think I'll ammend my plans and only drill one side with 3 drains and the overflow, and do a closed loop for the rest of the day 1 flow, and augment from there as needed.

I'm thinking should be able to get 1200-2000 (as needed) through the sump with the one side overflow. I'll have to do some research on the closed loop flow, but it seems pretty straightforward, and I dont really need to solve that at this stage of the build.

I'm certainly glad I posted, as cutting the drilling in half will help me get some sleep while i wait for the biamond hole saws to arrive on Monday.

Thanks for the suggesitons everyone.

CHSUB · 02/11/2012, 04:03 PM

Quote:

Originally Posted by Rybren

I do believe that you are confusing in-tank flow with flow through the overflow and sump system.

For in-tank flow, 10-20x (or more) is generally fine. SPS tanks tend to have more flow (up to 40x) than LPS or Sofites tanks. In-tank flow is generally achieved by using powerheads or a closed loop system.

For the overflow/sump system, you generally want significantly less flow, perhaps up to a MAXIMUM of 10x the system volume.

this is exactly true, no need to run all your flow through the sump, my last sps system had 70x flow, not possible through the sump!!!!

Rybren · 02/11/2012, 04:36 PM

Quote:

I'll have to do some research on the closed loop flow, but it seems pretty straightforward, and I dont really need to solve that at this stage of the build.

Actually, you may need to consider it at this stage. Most, but not all, closed loops run via holes drilled in the bottom of the tank. I believe you mentioned that the bottom is tempered, so drilling the bottom is out.

Next, some folks will drill the back of the tank, but since yours is see through, that option is out.

You could drill the ends, but I don't know that you'd be able to achieve very good flow dynamics.

You could also run the intake and return over the sides, but it may be unsightly.

Pillgrimm · 02/11/2012, 04:54 PM

I'm planning on running all my returns over the wall. Specific placement I'm still working out, but not critical since I will be trimming all around the tank, and the uppers above the tank will conceal everything except that which protrudes into the tank, which should be manageable. When it's complete, you wont see anything but glass from either room.

Rybren · 02/11/2012, 09:05 PM

Sounds good. Good luck.

02/10/2012, 11:50 AM	#1
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	Overflow/Drain Design Validation First of all, I'd like to say Hello to everyone. I've been lurking in these forums for many moons, but haven't joined until just today. It feels like a great community, and I've absorbed a wealth of information, and am lookoing forward to being an active participant as I learn my way around the reef keepng realms. I started a project several months back where I'll end up with a through wall tank. 72x24x30 were my original plans. I've done most of the framing, and the stand work already, and will be finishing and trimming as I get the tank in and plumbed. I was in the process of having the tank custom ordered, and pre-drilled with internal overflows on the short ends, and bulkheads in the bottom. Right as I was preparing to pull the trigger on that order, I did some ebay and cragslist scanning and found a terrific deal on a 180-ish (72x24x24). For 100$ I couldnt pass it up. It's not drilled anywhere, and is standard trim braced all around. So this brings me to my dilemma... I've read dozens and dozens of posts reharding HoB vs internal, etc, and I've decided that it's worth the risk to drill it out and run internal overflows. Worst case, I'm out the 100$, plus the 20-ish for the hole saw, and back to the custom order scenario, with a bunch of glass to dispose of :-/ . I won't be drilling the bottom, as it's tempered, so I'll be coming in the short sides near the top. This means I'll have to reframe some of the bookshelf work on either side of the stand, but...meh, not the end of the world. After lots of reading in these forums, I've decided I'm enamored of the overflow and drain designs in the BeanAnimal Silent Overflow threads. So here's where my concerns come in: With the 180, and a full reef setup, I understand I should be shooting for somewhere near 3000-3200 gph of flow through the tank. Because of the through-wall design, I have to do the overflows and drains on the short ends. I like the calfo(?) edge to edge overflow, and as I mentioned, I like the 3 drain silent + failover designs in the threads I referenced, so my plan is to replicate that setup with one overflow on each short end, spanning the whole 24 inches, with around a 6"x6" internal box, and three 1.75" holes for 1" bulkheads drilled into the sides. This should, if I've understood the math correctly, allow me to handle up to 4000 gph. Again, that's assuming I've got the fundamentals down, which admittedly is a big assumption. My biggest question is, is this overkill? Am I crossing a risk/return threshold with the 6 holes? At the very least, I've almost convinced myself that I don't need TWO of the emergency drains, so maybe only 5 holes is required. One side with a full siphon, open siphon and emer drain, and one side with just a full and open siphon. I would love to hear some thoughts on this scenario. Any guidance or advice would be appreciated. I'm also more than willing to re-post on those threads regarding overflow specifics, but was trying to honor the "new guy" posting recomendations. Thanks

02/10/2012, 06:45 PM	#5
Agu Registered Member Join Date: Oct 1999 Location: Sarasota, Florida Posts: 30,279	*To Reef Central* As others have pointed out you probably don't need that much flow in the DT. Also you don't want that much flow through a sump system as it could be quite loud and splash a lot creating salt creep. When I had a 180 reef ready I only ran about 900 GPH through the sump and supplememted with powerheads. Back then powerheads like the VorTech with the power part outside the tank weren't available. With that type of powerheads you'll have redundancy, more flexibility, and still have minimal equipment visible in your tank. I'd suggest you scale down the overflow plans and supplement flow by other means. __________________ Less technology , more biology . Current Tank Info: 30 gallon half cube and 5.5, both reef tanks

02/10/2012, 07:45 PM	#7
Agu Registered Member Join Date: Oct 1999 Location: Sarasota, Florida Posts: 30,279	Pillgrimm is planning a through the wall tank visible on both sides as I understand it. That's why he wants to put overflows on the ends. __________________ Less technology , more biology . Current Tank Info: 30 gallon half cube and 5.5, both reef tanks

02/11/2012, 03:19 PM	#15
uncleof6 Registered Member Join Date: Jul 2004 Location: AWOL Posts: 12,013	Sounds like an attempt to deal with possible crook issues, which need to be dealt with by the use of a jointer, rather than a flexible layer. In terms of small imperfections, and pressure spots between the top of the stand frame and the bottom of the plywood top, there is nothing to be gained by the use of a flexible base, its use is pointless. On the other hand, uneven settling of the foam, could lead to any number of pressure issues that will be transmitted up to the tank. You want the tank sitting on a firm solid surface. And in fact with a rimmed tank, the tank does not even need to sit on a sheet of plywood, only the rim of the stand framework. The only time small imperfections, and pressure points are of any concern, is on the TOP SIDE of the top, and with a tank that has no rim, and the bottom glass sits directly on the plywood. I think you have been reading TOO much __________________ "Things should be made as simple as possible, but not simpler." (oft attributed to Einstein; most likely paraphrasing by Roger Sessions; compactly articulates the principle of Occam's Razor) Current Tank Info: 325 6' wide Reef Last edited by uncleof6; 02/11/2012 at 03:25 PM.

02/11/2012, 09:05 PM	#21
Rybren Registered Member Join Date: Apr 2009 Location: Ottawa, Canada Posts: 1,642	Sounds good. Good luck. __________________ 120G Mixed Reef, 28G AIO zoa/pipefish tank

02/10/2012, 01:43 PM	#2
redfishblewfish Registered Member Join Date: Nov 2008 Location: Central New Jersey Posts: 716	I'm not sure where you got your turnover numbers from, but I've always used 6-10 times the DT volume per hour. So if you have a 180 gallon DT, you are looking at 1080 to 1800 gph. I've seen the post about the Beananimal, and it looks interesting, and has gotten very positive feedback. However, you need to be a DIY'er to put those things together. I really like Glass-Holes kits...and it includes the drill bit! Buy it, drill it, done! I'm extremely happy with my 1500 gph kit.

02/10/2012, 02:22 PM	#3
tangs_tank Registered Member Join Date: Jan 2012 Location: Grayslake, Il Posts: 135	I have a 180 glass DT which I purchased new by Oceanic. It was reef-ready so overflows were pre-finished. I called Oceanic and the overflows were made for 1200gph, 600 each side. That being said, I'm no expert but I took the manufacture's word and now plumbed and running great. The numbers you gave on the other hand is kinda hugh.

02/10/2012, 04:58 PM	#4
Playa-1 Moved On Join Date: Jun 2007 Location: Laguna Niguel, CA Posts: 7,497	If it were mine, I would be planning to push roughly 1000 gph turnover thru the sump and the rest of the flow in the Display would be coming from powerheads. I would be likely be aiming for 5500gph of flow in the DT from all sources combined to start and then adjusting as necessary. I would recommend keeping the drilling to a minimum.

02/10/2012, 07:28 PM	#6
slenhart1018 Registered Member Join Date: Jan 2012 Posts: 16	I am in a similar position as you. I have a 180 gallon I am setting up. I am also looking into the bean animal overflow. My first question to you is: What is going to be behind the tank? a fish room? why not just drill 3 holes for 1 1/2" bulkheads, and do a coast to coast overflow? have your returns to the dt come through the left and right sides? Or make a box on the back wall, like, shorten the coast to coast and have the return come out on either side of that? My plan is to use (3) 1 1/2" bulkheads for the overflow and (2) 1" bulkheads for the returns, although I havent figured out where I want them just yet. As for the flow, Im not to good with that yet, but Im figuring on using a mag 9.5 and supplementing the rest with 2 koralia 1400 powerheads. Someone please correct me if im wrong.

02/11/2012, 07:49 AM	#9
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	Thanks for the feedback from everyone so far. My design principles on this, and most other DIY projects I attempt, has been Over engineered is better than under. This is my first reef tank, so I'm not 100% on where that principle might steer me astray yet. I'm interested in the disparity on recomendations related to flow volume. Most of my reading on these forums, and a few others, has led me to believe that I should be shooting for 10-20x turnover per hour. I recognize that I could supplement with powerheads, and may have to based on specific flow-needy parts of the tank, but I'd much prefer to not. With the coast to coast overflows, coupled with the 3 drain design we've referenced, almost all applications I have seen have been 40-72" in length on the overflow. The part I am struggling with, since I must put my overflows on the short ends, as it's through wall, is whether that 24" of overflow will be enough to support the turnover flow I need. I'd much rather not drill both sides, as I give Murphy's law a chance to creep in, in direct proportion to the number of holes I drill. However, I am afraid that if I do not, I will one day wish I had. Does length of horizontal overflow impact the drain flow volume? Or is the only limiter the bulkhead and pipe size flow restrictions? Would it impact the quality of surface skimming?

02/11/2012, 08:28 AM	#10
Playa-1 Moved On Join Date: Jun 2007 Location: Laguna Niguel, CA Posts: 7,497	If you are trying to get away from powerheads then you may want to consider a closed loop circulation system that is separate from the sump.

02/11/2012, 08:41 AM	#11
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	Thanks for the advice. I think that's worth exploring. Maybe half the flow into the sump and half through a closed loop, to avoid messes and noise in the sump? In the context of my drain design, I wonder if I could simply plumb the 3 drain side as described, drilled and all, and do hang-overs on the other short end for the drain and return on the closed loop?

02/11/2012, 08:56 AM	#12
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	While I'm at it, I thought I would post some pics of the build. All the framing is complete. I'll be adding the 3/4" shelf to the top of the stand today, with 1/4" foam under the ply. Clearly nothing is trimmed or finished, as I can't do that until I sort out the plumbing and hood design. One thing at a time... http://s1168.photobucket.com/albums/r492/Pillgrimm/

02/11/2012, 03:07 PM	#14
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	The foam under the stand top will give me a good stable transfer for the top surface. It will level out small imperfections and pressure spots between the ply top and the stand frame. The stand is 4x4 post and beam, so i could park a bus on it and not have stability issue, I think. I've read a lot of heated debate on the use of foam for pressure levelling, and while I wont use it under this tank, as it's trim braced, and the ply surface should give me a good platform, I do think it will add value under the top surface.

02/11/2012, 04:54 PM	#20
Pillgrimm Registered Member Join Date: Feb 2012 Posts: 9	I'm planning on running all my returns over the wall. Specific placement I'm still working out, but not critical since I will be trimming all around the tank, and the uppers above the tank will conceal everything except that which protrudes into the tank, which should be manageable. When it's complete, you wont see anything but glass from either room.