Drilling a 90G - Internal Overflow Help

nc87 · 10/19/2009, 09:33 AM

Hi All,

I just purchased a 90G (48x18x24) aquarium from a fellow reefer to replace the 55G tank that I have now. I wanted to get the tank drilled and run a sump/fuge on the system. I'm just confused as to how it should be setup. I've looked at some pics and threads about drilling and plumbing the tank, but I'm still confused. What I'm thinking of doing is drilling the tank from the bottom in the back of the tank with the overflow sitting in the middle of the back wall (1 hole for the drain and 2 holes for the return). From what I understand my best option is to use a stand up Durso pipe as the drain. It's also my understating that I should aim for a turnover rate of 10x amount of my tank, so in my case 900 GPH.

So here's my questions...

1) How does my drain/return sound? for the drains I was thinking of bringing them through the overflow rather than over the tank. I think this gives it a cleaner look and everything is hidden behind the overflow.

2) When I enter 900 GPH into the Overflow & Drain Calc I get a linear overflow length of 14.26, so I was thinking 3" x 8.26" x 3" for the internal overflow... but that seems kind of small.

3) The Drain pipe diameter i get is 1.24 so essentially 1 1/4" , but I don't understand what is meant by "each dual drain pipe diameter (.88")" and "each dual linear overflow length (7.13")"

4) From what I've read, it appears I have to have the glass tempered after it is drilled, I just wanted to confirm this.

I'm sure I'll have more questions as I progress on the project, any advice/help/opinions are greatly appreciated.

Thanks,

der_wille_zur_macht · 10/19/2009, 09:47 AM

First, you need to decide what your priorities and objectives are. Do you want the best performance? Quietest operation? Cleanest look? In the last few years, there have been a proliferation of new styles of overflow, so the standard small box with a Durso through the floor isn't quite the standard any more.

Many people have their favorite style of overflow and drain configuration, but IMHO you need to decide what your objectives are and then start from there, rather than just picking something that someone else says is best.

And - no - you don't have to get the glass tempered after drilling. Perhaps you're thinking of tanks that are manufactuered with the goal of being tempered from the start - the glass used in such tanks has to be cut and drilled before tempering, but if your tank is structurally sound and not tempered, you don't have to worry about it. Plus, to get that glass tempered, you'd have to basically disassemble the tank and rebuild it, since you can't temper an assembled tank!

nc87 · 10/19/2009, 10:08 AM

Thanks, for the reply. My main objective would be performance and Quietest operation. I'm looking to drill from the bottom with an internal overflow because I want the tank to sit right against the wall.

uncleof6 · 10/19/2009, 10:26 AM

Quote:

Originally Posted by nc87

Hi All,

I just purchased a 90G (48x18x24) aquarium from a fellow reefer to replace the 55G tank that I have now. I wanted to get the tank drilled and run a sump/fuge on the system. I'm just confused as to how it should be setup. I've looked at some pics and threads about drilling and plumbing the tank, but I'm still confused. What I'm thinking of doing is drilling the tank from the bottom in the back of the tank with the overflow sitting in the middle of the back wall (1 hole for the drain and 2 holes for the return). From what I understand my best option is to use a stand up Durso pipe as the drain. It's also my understating that I should aim for a turnover rate of 10x amount of my tank, so in my case 900 GPH.

So here's my questions...

1) How does my drain/return sound? for the drains I was thinking of bringing them through the overflow rather than over the tank. I think this gives it a cleaner look and everything is hidden behind the overflow.

2) When I enter 900 GPH into the Overflow & Drain Calc I get a linear overflow length of 14.26, so I was thinking 3" x 8.26" x 3" for the internal overflow... but that seems kind of small.

3) The Drain pipe diameter i get is 1.24 so essentially 1 1/4" , but I don't understand what is meant by "each dual drain pipe diameter (.88")" and "each dual linear overflow length (7.13")"

4) From what I've read, it appears I have to have the glass tempered after it is drilled, I just wanted to confirm this.

I'm sure I'll have more questions as I progress on the project, any advice/help/opinions are greatly appreciated.

Thanks,

4) To temper the glass, after you have finished drilling it, the tank would need to be disassembled, the glass panel taken to be tempered, and then the tank reassembled. A very big chore, and does not need to be done. I really don't think this is something that you want to do either. It is more likely that the bottom glass is already tempered, and you cannot drill it.

3) The calculator does give 1.25" (1.24") as minimum diameter pipe, for 900 gph. I don't know where the "dual" comes from, unless you are intending to put two separate overflows in the tank. Looks like your plan describes a single overflow box in the tank.

A single 1.25" durso will not flow 900 gph reliably. There would be far too much turbulence in the drain pipe. Flow through a durso needs to be slow enough to be non turbulent, or "laminar" (water flowing down the walls of the drain line with air in the middle.) A 1.25" durso, will probably not flow 320 gph reliably, though a 1.5" durso probably would. But this is nowhere near your target flow rate. (and your target flow rate is fine)

2) The calculator calls for 14" linear overflow length (without teeth). Again I don't know where "dual" comes from.

You are right in feeling that this length is a bit small. The calculator calculates the minimum for a specified flow rate, however it does not relate to what will give the most efficient surface skimming. The longer the weir (top edge of the overflow) the more efficiently the surface layer of water (that is where the organics collect) will be removed from the tank.

1) Your ideas will work, and are typically the way "reef ready" tanks have been made for quite a long time. However, the limitations of this design have led to better more efficient designs.

Since you are planning on drilling the tank, and it is likely that you may not be able to drill through the bottom of the tank, a better option would be to drill through the upper back of the tank, use a long shallow overflow, and a silent and trouble free drain system.

http://reefcentral.com/forums/showth...5&pagenumber=1

HTH,

Jim

Mr Coffee · 10/19/2009, 08:37 PM

+1 on the last method. This is the one that I intend to use on my 90G I just purchased.

While I am sure that you would like the tank to be against the back wall this method does not lend itself to that design requirement. I honestly can not tell that my tanks are not against the wall. Having a tank away from the wall makes working on them much easier. I have seen a tank that some one used a black border around this gap between the rear of the tank and the wall that enabled them to hide wires ect but ended up being a nice touch.
If your tank is directly against the wall you will have the wires for the pumps ect coming up the side of the tank which may not be the look you are after.
There is another thread about drilling tanks that you need to read directly below this one.
http://www.reefcentral.com/forums/sh....php?t=1724823
This talks about various methods for figuring out if you can drill a tank
Just to be clear you can not drill a piece of glass that is tempered. You have to drill un-tempered glass only.
I was actually going to post pics of a tank to get it ID'ed so that I could attempt to contact the manufacturer. Just to ensure that I am doing all my due diligence before placing a drill on the tank.
Good luck let us know what you decide to do and how well it works or does not when you are done.
Feedback is everything in this hobby.

nc87 · 10/22/2009, 12:53 PM

Here's what I've got planned so far. I borrowed this from another reefer and adjusted it for my setup. The drain doesn't have to be a Durso , it's just pictured that way. Obviously, I'm only using this plan if I can drill from the bottom, otherwise I'll drill from the back.

The return line would come up through the overflow (where the black circle is) and the return line would be t'd off to the fuge. I'm thinking of changing the drain size to 1 1/4" to get 900GPH and the internal overflow would be 3"(W) x 8.26"(L) x 24"(H).

What do you guys think?

salt h20 · 10/22/2009, 02:15 PM

Make the overflow wider, say 6x10x24. Drill one side about 3/4 of the way up, and install a bulkhead facing out. 90 this down inside the overflow, and attach another bulkhead at the bottom though the tank for your return. If you measure carefully, the whole thing can be assembled outside tank, and installed as a unit. Or use a short run of spa flex or vinyl between the two bulkheads. Then your return is truly hidden. You can tee your return line directly above the sump for the fuge. You may need to install a check valve on the return line if your sump is small.
BTW, the local Childrens Hospital has the return in the overflow. The maintenance company had the builder put a box inside the face of the overflow, and slotted the front of the overflow. It truly is hidden, but you can notice the flow exiting the front of the overflow box. Pretty trick.

avaneaton2000 · 10/22/2009, 04:02 PM

Your design will break your tank, the bottom of 90g's are tempered. Drill one of the sides. Also a bottom drilled overflow takes up too much real estate. Additionally the lazy wye you want to use the left return will have much more flow than the right.

uncleof6 · 10/22/2009, 04:07 PM

Quote:

Originally Posted by nc87

Here's what I've got planned so far. I borrowed this from another reefer and adjusted it for my setup. The drain doesn't have to be a Durso , it's just pictured that way. Obviously, I'm only using this plan if I can drill from the bottom, otherwise I'll drill from the back.

The return line would come up through the overflow (where the black circle is) and the return line would be t'd off to the fuge. I'm thinking of changing the drain size to 1 1/4" to get 900GPH and the internal overflow would be 3"(W) x 8.26"(L) x 24"(H).

What do you guys think?

I will wait till you redesign it. (Tempered bottom) Also a 1.25" air/water mix modified (aka durso, stockman) stand pipe will not flow 900 gph reliably, quietly, and bubble free.

Jim

nc87 · 11/16/2009, 08:57 PM

Ok, so I just confirmed that the tank is not tempered and am planning to drill a drain & return line through the bottom of the tank. It seems everyone is recommending a 1.5" drain, which would give me 1300 GPH. I'm still confused about the return line, just want to make sure.... 1" return line back to the main display. My overflow will have a linear length of 20.55", so most likely 3" x 14.55" x 3".

I've never drilled a tank before (I'm taking it to a place that deals with glass), does the holes have to be the same size as the pipes? It's my understanding that they should be bigger and then I put a bulkhead on the hole the size of the pipe.

Also, what kind of bulkhead should I be using? can anyone recommend a brand?

I picked up a skimmer, RS-80, from a reefer on here and I'm in the process of finishing my stand & starting the Sump . I'll post some pics of the stand later on if I get a chance. Thanks for the help so far guys!

uncleof6 · 11/16/2009, 11:32 PM

Quote:

Originally Posted by nc87

Ok, so I just confirmed that the tank is not tempered and am planning to drill a drain & return line through the bottom of the tank. It seems everyone is recommending a 1.5" drain, which would give me 1300 GPH. I'm still confused about the return line, just want to make sure.... 1" return line back to the main display. My overflow will have a linear length of 20.55", so most likely 3" x 14.55" x 3".

I've never drilled a tank before (I'm taking it to a place that deals with glass), does the holes have to be the same size as the pipes? It's my understanding that they should be bigger and then I put a bulkhead on the hole the size of the pipe.

Also, what kind of bulkhead should I be using? can anyone recommend a brand?

I picked up a skimmer, RS-80, from a reefer on here and I'm in the process of finishing my stand & starting the Sump . I'll post some pics of the stand later on if I get a chance. Thanks for the help so far guys!

You will not get 1300 gph through a 1.5" drain line unless it is a full siphon. If it is durso modified or any variation there of, you will be very lucky to get 400 gph through it reliably with out gurgling, water level fluctuations, and a lot of bubbles.

If you run the 1.5" drain as a full siphon, you need emergency back up for it: Another DRY 1.5" standpipe.

Also, if you cut teeth in your overflow, cut the linear length you will have in half roughly.

Regards,

Jim

IJayC1 · 11/17/2009, 11:05 PM

id just go to glass-holes.com and get their 1500 gph kit, but thats just my .2

uncleof6 · 11/18/2009, 01:26 AM

Quote:

Originally Posted by IJayC1

id just go to glass-holes.com and get their 1500 gph kit, but thats just my .2

That is not a bad $.02 just for the record.

Jim

10/19/2009, 09:33 AM	#1
nc87 Registered Member Join Date: Apr 2006 Posts: 23	Drilling a 90G - Internal Overflow Help Hi All, I just purchased a 90G (48x18x24) aquarium from a fellow reefer to replace the 55G tank that I have now. I wanted to get the tank drilled and run a sump/fuge on the system. I'm just confused as to how it should be setup. I've looked at some pics and threads about drilling and plumbing the tank, but I'm still confused. What I'm thinking of doing is drilling the tank from the bottom in the back of the tank with the overflow sitting in the middle of the back wall (1 hole for the drain and 2 holes for the return). From what I understand my best option is to use a stand up Durso pipe as the drain. It's also my understating that I should aim for a turnover rate of 10x amount of my tank, so in my case 900 GPH. So here's my questions... 1) How does my drain/return sound? for the drains I was thinking of bringing them through the overflow rather than over the tank. I think this gives it a cleaner look and everything is hidden behind the overflow. 2) When I enter 900 GPH into the Overflow & Drain Calc I get a linear overflow length of 14.26, so I was thinking 3" x 8.26" x 3" for the internal overflow... but that seems kind of small. 3) The Drain pipe diameter i get is 1.24 so essentially 1 1/4" , but I don't understand what is meant by "each dual drain pipe diameter (.88")" and "each dual linear overflow length (7.13")" 4) From what I've read, it appears I have to have the glass tempered after it is drilled, I just wanted to confirm this. I'm sure I'll have more questions as I progress on the project, any advice/help/opinions are greatly appreciated. Thanks,

10/19/2009, 09:47 AM	#2
der_wille_zur_macht Team RC Member Join Date: Sep 2003 Location: NY Posts: 17,749	First, you need to decide what your priorities and objectives are. Do you want the best performance? Quietest operation? Cleanest look? In the last few years, there have been a proliferation of new styles of overflow, so the standard small box with a Durso through the floor isn't quite the standard any more. Many people have their favorite style of overflow and drain configuration, but IMHO you need to decide what your objectives are and then start from there, rather than just picking something that someone else says is best. And - no - you don't have to get the glass tempered after drilling. Perhaps you're thinking of tanks that are manufactuered with the goal of being tempered from the start - the glass used in such tanks has to be cut and drilled before tempering, but if your tank is structurally sound and not tempered, you don't have to worry about it. Plus, to get that glass tempered, you'd have to basically disassemble the tank and rebuild it, since you can't temper an assembled tank! __________________ Inconveniencing marine life since 1992 "It is my personal belief that reef aquaria should be thriving communities of biodiversity, representative of their wild counterparts, and not merely collections of pretty specimens growing on tidy clean rock shelves covered in purple coralline algae." (Eric Borneman)

10/19/2009, 08:37 PM	#5
Mr Coffee Registered Member Join Date: Feb 2009 Location: Nashville, TN Posts: 511	+1 on the last method. This is the one that I intend to use on my 90G I just purchased. While I am sure that you would like the tank to be against the back wall this method does not lend itself to that design requirement. I honestly can not tell that my tanks are not against the wall. Having a tank away from the wall makes working on them much easier. I have seen a tank that some one used a black border around this gap between the rear of the tank and the wall that enabled them to hide wires ect but ended up being a nice touch. If your tank is directly against the wall you will have the wires for the pumps ect coming up the side of the tank which may not be the look you are after. There is another thread about drilling tanks that you need to read directly below this one. http://www.reefcentral.com/forums/sh....php?t=1724823 This talks about various methods for figuring out if you can drill a tank Just to be clear you can not drill a piece of glass that is tempered. You have to drill un-tempered glass only. I was actually going to post pics of a tank to get it ID'ed so that I could attempt to contact the manufacturer. Just to ensure that I am doing all my due diligence before placing a drill on the tank. Good luck let us know what you decide to do and how well it works or does not when you are done. Feedback is everything in this hobby. __________________ I dose coffee Current Tank Info: 75 & 90 now a 210 build in progress

10/22/2009, 02:15 PM	#7
salt h20 Registered Member Join Date: Oct 2009 Location: Midwest, Illinois Posts: 24	Make the overflow wider, say 6x10x24. Drill one side about 3/4 of the way up, and install a bulkhead facing out. 90 this down inside the overflow, and attach another bulkhead at the bottom though the tank for your return. If you measure carefully, the whole thing can be assembled outside tank, and installed as a unit. Or use a short run of spa flex or vinyl between the two bulkheads. Then your return is truly hidden. You can tee your return line directly above the sump for the fuge. You may need to install a check valve on the return line if your sump is small. BTW, the local Childrens Hospital has the return in the overflow. The maintenance company had the builder put a box inside the face of the overflow, and slotted the front of the overflow. It truly is hidden, but you can notice the flow exiting the front of the overflow box. Pretty trick. __________________ When I woke up today, I thought I could change the world.... Ace Frehley Current Tank Info: 65 gallon acrylic

11/17/2009, 11:05 PM	#12
IJayC1 Registered Member Join Date: Nov 2008 Location: South Dakota Posts: 103	id just go to glass-holes.com and get their 1500 gph kit, but thats just my .2 __________________ Jay Current Tank Info: mostly softies and lps looking tp start sps shortly

10/19/2009, 10:08 AM	#3
nc87 Registered Member Join Date: Apr 2006 Posts: 23	Thanks, for the reply. My main objective would be performance and Quietest operation. I'm looking to drill from the bottom with an internal overflow because I want the tank to sit right against the wall.

10/22/2009, 12:53 PM	#6
nc87 Registered Member Join Date: Apr 2006 Posts: 23	Here's what I've got planned so far. I borrowed this from another reefer and adjusted it for my setup. The drain doesn't have to be a Durso , it's just pictured that way. Obviously, I'm only using this plan if I can drill from the bottom, otherwise I'll drill from the back. The return line would come up through the overflow (where the black circle is) and the return line would be t'd off to the fuge. I'm thinking of changing the drain size to 1 1/4" to get 900GPH and the internal overflow would be 3"(W) x 8.26"(L) x 24"(H). What do you guys think?

10/22/2009, 04:02 PM	#8
avaneaton2000 Registered Member Join Date: Nov 2007 Location: Hillsboro Beach, FL Posts: 732	Your design will break your tank, the bottom of 90g's are tempered. Drill one of the sides. Also a bottom drilled overflow takes up too much real estate. Additionally the lazy wye you want to use the left return will have much more flow than the right.

11/16/2009, 08:57 PM	#10
nc87 Registered Member Join Date: Apr 2006 Posts: 23	Ok, so I just confirmed that the tank is not tempered and am planning to drill a drain & return line through the bottom of the tank. It seems everyone is recommending a 1.5" drain, which would give me 1300 GPH. I'm still confused about the return line, just want to make sure.... 1" return line back to the main display. My overflow will have a linear length of 20.55", so most likely 3" x 14.55" x 3". I've never drilled a tank before (I'm taking it to a place that deals with glass), does the holes have to be the same size as the pipes? It's my understanding that they should be bigger and then I put a bulkhead on the hole the size of the pipe. Also, what kind of bulkhead should I be using? can anyone recommend a brand? I picked up a skimmer, RS-80, from a reefer on here and I'm in the process of finishing my stand & starting the Sump . I'll post some pics of the stand later on if I get a chance. Thanks for the help so far guys!