This is brilliant. :thumbsup:
Silent and Failsafe Overflow System
- Thread starter JohnL
- Start date
This is brilliant. :thumbsup:
some pictures with my silicon painted overflow:
[IMG=http://img834.imageshack.us/img834/6531/24042011202.th.jpg][/IMG]
The glass, was not clened,but i assure you, it looks very good.
[IMG=http://img834.imageshack.us/img834/6531/24042011202.th.jpg][/IMG]
The glass, was not clened,but i assure you, it looks very good.
Picked up the 1" bulkheads last night, now waiting for the drill to come in the mail.... Hopefully the drilling will be a success this weekend.
I have a 72g bow front and looking to make the overflow about 18" wide, centered in the middle (deepest part) on the back glass. Anyone object to this idea? not looking to go c to c on this one.
Then I'm wondering how tall to make the overflow and spacing for the wier? Also how far down from the top of the tank should I make the centerline for the three bulkheads?
Thanksg
Gus
I have a 72g bow front and looking to make the overflow about 18" wide, centered in the middle (deepest part) on the back glass. Anyone object to this idea? not looking to go c to c on this one.
Then I'm wondering how tall to make the overflow and spacing for the wier? Also how far down from the top of the tank should I make the centerline for the three bulkheads?
Thanksg
Gus
All these configurations can be confusing 'till you get it setup then it all makes sense and you know exactly what you would have wanted!
So, you're putting an overflow box on the outside of the back, right? Are you also building one on the inside as well?
How are you going to get water into the overflow box? Glass tank, right? And you checked for plain glass you want to drill?
Guess I missed a few details.
This will be an internal overflow box, tank is glass and drill is in the mail. The set up will be exactly as per Bean, without the coast to coast. if I had a much larger tank I'd love to do that. On this one I'm trying to keep it centered, insided the tank, on the back glass. Roughtly 18" wide.
Thanks
GUs
This will be an internal overflow box, tank is glass and drill is in the mail. The set up will be exactly as per Bean, without the coast to coast. if I had a much larger tank I'd love to do that. On this one I'm trying to keep it centered, insided the tank, on the back glass. Roughtly 18" wide.
Thanks
GUs
That should work fine.
What are you going to use for the weir? The part the water flows over?
Sounded like you were making the box out of glass, pretty hard to cut teeth. Internal boxes can also be made from acrylic, easier to cut teeth, siliconed in. I didn't have any issues sealing acrylic baffles into a glass sump. Some have glued on a strip of acrylic on top of a glass box with the teeth cut in it. Egg-crate will also work, can be siliconed onto the length of the weir (just an idea). Just bear in mind whatever the level of the spillway, your tank waterlevel will run about a quarter inch above that with a normal flow (4-600gph). Some claim no teeth works fine, fish won't go over it, but it all depends on how much water is going over the waterfall. In this case a screen on the intake pipe may make sense to keep them out of the sump. 18" of spillway will provide a good amount of surface skimming capability, plus the width of the box, so if that is say 3", you actually get 24 linear inches. Mine weir is 22" long, at 450gph the water is about a quarter inch tall going over the weir. I put eggcrate up to help keep critters in the tank.
The drain BH's are not critical as long as they are below the level you wish to have the water level of the tank. You just need room for the elbows to turn down, so leave yourself an inch or so from the bottom of your box to the bottom of the elbow drain inlet. You need a half inch or more anyway just for the BH flange, so if you add another half inch you should be good. All depends on the pipe fitting sizes you're using, you want to leave enough room to get everything in there. I would get all the plumbing parts and lay it out dry and see how the dimensions work out.
If you're running a normal flow of water then 1" BH's set an inch or two below your waterlevel will work fine. I would shoot for the centerline to be 2" below the tank waterlevel. Will make tuning the drains easier. Many have recommended that the full siphon pipe be a half to one inch below the durso pipe to help force the full siphon to start automatically. The original design had them set the same height. When I tested mine I could only get the full siphon to go if I opened the tuning valve to flush the air out of it, then re-tuned it. Some have said this is due to the ball valve being closer to the box instead of lower down by the sump. Anyway, mine is a lot easier to set the box water height because I can just shorten or lengthen the standpipes. Once you cut your BH holes your waterlevel is fixed. Maybe Bean himself can comment on this.
The full open can be adjusted with a turned up elbow so it's height can be easily set - this is your emergency water level height. Whatever the height is of your vented drain is where your box waterlevel will be. If it's much below the tank waterlevel you'll get noise from the spillway over the weir. Shooting for less than 2" is recommended. That way your box does not have to be very tall either. All depends if you want to hide all the plumbing or if it's okay for the vented drain pipe to stick up above the top of the tank. Here's a good drawing of exactly what you have described, from ealier in the thread: http://reefcentral.com/forums/showpost.php?p=14040940&postcount=992
Hey cjbrown,
Thanks for your feedback. Hopefully going to lowes tonight to pick up all the pvc pipe and elbows. Your right once I have all the pieces I'll play around with them to get a sense of everything you mention. Thanks for the details, gives me a starting point.
I was going to pick up a piece of black acrylic (if I can find it, lowes sells 1/4" clear acrylic). I was going to make a jig and cut the wier slots on a table saw (at least try) but the egg crate idea sounds even better.
Will post updates.
Thanks
gus
Thanks for your feedback. Hopefully going to lowes tonight to pick up all the pvc pipe and elbows. Your right once I have all the pieces I'll play around with them to get a sense of everything you mention. Thanks for the details, gives me a starting point.
I was going to pick up a piece of black acrylic (if I can find it, lowes sells 1/4" clear acrylic). I was going to make a jig and cut the wier slots on a table saw (at least try) but the egg crate idea sounds even better.
Will post updates.
Thanks
gus
Sounds good. Did you start a build thread yet?
They don't have black acrylic, just clear. At least that's for HD, my preferrence is Lowes but our HD is a bit closer. We have an acrylic manufacturer close by though and they have scraps and full sheets in stock. If you don't have a good source I would be willing to pickup what you need and ship it to you. The surplus is like $2 a pound. My overflow box was just scrap surplus already cut to size.
The slots are difficult with a table saw, the piece really needs to be run vertical so the kerf is flush. You could setup a jig. I used a 60 tooth blade and it cut it fine although a little rough. For welding seams the edge can be dressed with a knife blade. Cutting weir teeth would a lot tougher to get them smooth - an 80-100 tooth blade might work better but big $$. This site recommends cutting them with a router, he's got a jig layout and everything:
http://www.melevsreef.com/allmysumps.html I poured over this site before getting started. Also, James moderates a thread here on acrylic building, very informative and helluva nice guy. Let me know if you can't find it.
The problem with eggcrate is the holes are pretty big. If you glue a strip on top of a wier the water probly won't even cover the first hole level. You do get the vertical section of the crate, but that's not much. Screen can also be added over crate, but then it all gets too complicated for me. :lmao:
I would guess if you kept the center lines equal you should be able to get some adjustment in height by adding or cutting down the elbows as necessary? I guess its something i may need to contend with soon. Eta for the drill is sat..
Will let you know on the acrylic
Thanks gus
Will let you know on the acrylic
Thanks gus
It's not the inlet height for a turned down drain, it's the level of where the water begins to flow down. Since the full siphon will flow regardless of it's height, the other drain that takes the excess is the one that sets the water height in the overflow box. The durso style drain with the vent on top is generally the one to take the excess after the full siphon because it's covered and therefore muffled so you don't hear any water draining. Some use the full open drain to take the excess and make the vented drain the emergency as it will convert to full siphon as well if the vent line is covered by rising water.
BeanAnimal
Premium Member
As the system is designed, the open channel standpipe (the one with the air line) is used as the secondary drain.
The centerline of the secondary standpipe (for the most part) sets height of the water in the overflow box.
The centerline of the secondary standpipe (for the most part) sets height of the water in the overflow box.
Im with you guys now... I agree about the water height inside the overflow. for some reason i thought you were refering to the hight of the waterline in the tank.. i cant do anything until the weekend... Its killing me.
Bean. Any concerns with all three bulkheads on the same centerline?
Thanks
gus
Bean. Any concerns with all three bulkheads on the same centerline?
Thanks
gus
BeanAnimal
Premium Member
The system was designed with all 3 bulkheads on the same centerline and will work properly if built as described.
You can move the open channel centerline up if desired. This can aid in forcing the siphon to start in setups that don't follow the design and/or systems that need a deep water buffer over the siphon intake (systems with dump boxes, etc.)
You can move the open channel centerline up if desired. This can aid in forcing the siphon to start in setups that don't follow the design and/or systems that need a deep water buffer over the siphon intake (systems with dump boxes, etc.)
The 75 Gallon tank I just ordered has arrived, and gets drilled today. I was hoping someone could help me out as to the exact placement of the holes for best results. I would like it to either be on the far right or back of the top portion of the tank. The overflow box won't extend across the entire back of the tank unless it is highly recommended by you all. If I can get away with an overflow box that is as small as possible but still give the great results, so looking for dimensions on that as well.
thanks,
Damien
thanks,
Damien
The coast to coast overflow really does give the best results what I did was instead of going all the way across the back I took 6" off each side so I could have my returns hanging off the back and still get the same liner surface area.
As far as the holes go it should be on the first five pages of the original thread since I can't remember. One tip I so remember though is to drill your open channel hole .25" higher then the other two to make for easier tuning.
As far as the holes go it should be on the first five pages of the original thread since I can't remember. One tip I so remember though is to drill your open channel hole .25" higher then the other two to make for easier tuning.
#10
BeanAnimal
Registered Member
Join Date: Feb 2003
Location: Pittsburgh
Posts: 18,518
Yes, all (3) bulkheads placed on the same horizontal centerline. You are correct, the up-turned elbow is what sets the failsafe level.
In this particular tank the horizontal center for the 1" bulkheads is at 4.25" from the top of the trim.
The bottom panel of the overflow box is 6" from the top of the trim. I had to cut the bottoms off of the elbows to get them to fit properly, as the overflow was siliconed in place long before I came up with this plan!
The front edge over the overflow is at the bottom of the trim. This way, even with the return pump off, the waterline is never visible from the display side of the tank.
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That is what I found in one of the old old posts back in 2008. I followed it and placed them 4.25" from top of the trim, and every 4" from the right end of the tank. I am waiting on the call as to when the tank has been drilled. I have everything for the plumbing only difference is I am using all 1" PVC instead of the 1.5" That should still work I hope?
BeanAnimal
Registered Member
Join Date: Feb 2003
Location: Pittsburgh
Posts: 18,518
Yes, all (3) bulkheads placed on the same horizontal centerline. You are correct, the up-turned elbow is what sets the failsafe level.
In this particular tank the horizontal center for the 1" bulkheads is at 4.25" from the top of the trim.
The bottom panel of the overflow box is 6" from the top of the trim. I had to cut the bottoms off of the elbows to get them to fit properly, as the overflow was siliconed in place long before I came up with this plan!
The front edge over the overflow is at the bottom of the trim. This way, even with the return pump off, the waterline is never visible from the display side of the tank.
-------------------------------------------------------------------------------------
That is what I found in one of the old old posts back in 2008. I followed it and placed them 4.25" from top of the trim, and every 4" from the right end of the tank. I am waiting on the call as to when the tank has been drilled. I have everything for the plumbing only difference is I am using all 1" PVC instead of the 1.5" That should still work I hope?
There. The data is all in there, you just have to find it! :lol2:
I used 1" thin wall pvc and it works great. I think the original was 1-1/2" so that 'sanitary' tees could be sourced, and for large volume of flow the intakes wouldn't create suction vortices. The 'sanitary' style tee is not available in 1" pvc. Didn't bother me, there is so little water flowing down my secondary it's a non-issue.
Maybe Bean can remind us of why he used 1-1/2" for the piping. Maybe it was also to help prevent clogs. For larger tanks that will flow thousands of gallons the larger sizes make sense.
Well i did find places that made custom 1" sanitary Tee's but they were about $50 each. So I went with the standard T as well. I did manage to call before they drilled the tank so they will move the open channel hole a little higher then the other two.
I was thinking of going along with the 1.5" PVC, but I do not have the space. : (
Damien
I was thinking of going along with the 1.5" PVC, but I do not have the space. : (
Damien
Check out flexpvc.com they should have what ever you need at a good price.
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