Silent and Failsafe Overflow System

[BeanAnimal]

Re: 55G Acrylic Design Considerations

Re: 55G Acrylic Design Considerations

<a href=showthread.php?s=&postid=13614586#post13614586 target=_blank>Originally posted</a> by jeffrey_ropp
Bean,

Thanks for a terrific design and an even greater contribution by supporting all of us trying to implement it.

I'd like to use your design on a 55g acrylic tank. As you've mentioned in the thread, you suggest an external overflow given the lighting and space considerations. A few questions:

1) In such a configuration, we would cut a slot for the weir into the back of the tank. What's a "safe" height, structurally and flow-wise, from the top of the tank (mine has a top as well)?

The height of the slot (distance from the top of the tank) will dictate the basic water height in the display. The tank will be eurobraced so that should take care of the top edge of the slot. IF the box is not too deep, then the bottom panel of the box will stiffen the back panel of the tank. A center brace in the box will help if the box is deeper.

2) Should it be the full length of the tank (the whole point of maximizing surface)? How far from the sides should be considered "safe"?

I don't see a problem going the whole length of the tank. In that case the "slot" would be formed by the top edge of the back panel and the bottom plane of the eurobrace.

3) as for the slot itself, how tall should it be? I figure this is flow rate dependent but also should be minimized for critters, etc.

I am not sure what size return pump you will be using, but 3/8" should be plenty. You could make it a bit larger if needed and build attach a simple "cover" to fine tune its height.

4) I have 2 pre-existing holes drilled (3/4" return and 1 1/2" drain). Neither seem to be at appropriate levels. Should I simply cap them? Any thoughts on aesthetics?

I can't say without a photo.

5) To minimize the width of the overflow, would it make sense to align the elbows parallel to the length of the tank and plumb them thru the bottom of the overflow?

That is certainly an option. You will find that you will want to be able to get your hand into the box though...

6) Is it worth it to have an acrylic specialist do the work or could this be DIY if I've never worked with the materials (drilling nor weld-on)?

That is a tough call. I don't know your current skillset or your aptitude. You may want to consult a specialist and explain your project and ask some questions before you make a decision on who should do the work. You may want to try building the box before you attempt to cut the slot. See how things go working with acrylic. You may also want to consider that the toosl and time needed may exceed the cost of just having it done.


I hope that helps some. Let me know if I can be of further help.

 

[jeffrey_ropp]

Thanks Bean.

My tank is 48l x 13d x 20t and is constructed using 1/4" acrylic sheets.

If I understand correctly, the slot should be made where the top sheet and back sheet seams come together rather than slightly down in the back sheet itself? I certainly could make it lower without display issues.

As for the existing holes, I took a few shots to further describe my situation. And yes, I'm using my tank as a mini greenhouse.

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/F3YqtuStcMzcZWsXc3WQ_w"><img src="http://lh6.ggpht.com/JeffreyRopp/SQKR2MWLm4I/AAAAAAAAB2U/TbK2wBDitgE/s288/Coast%20to%20Coast%20Overflow.jpg" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/JeffreyRopp/Collages">Collages</a></td></tr></table>

Thanks again for your help!
Jeff

 

[shelburn61]

<a href=showthread.php?s=&postid=13614734#post13614734 target=_blank>Originally posted</a> by BeanAnimal
Shelburn. My skimmer is fed from the overflow box via a MaxiJet. The flow from the siphon standpipe is far too much for the skimmer. Other people have teed off the siphon standpipe with a valve to regulate the siphon feed with success. You could try doing the same thing.

ok, I'm guessing the valve to regulate the siphon will be followed by a Tee with a second valve to regulate flow to the skimmer?

 

[jimnrose]

Bean, I'm getting ready to drill holes for the bulkhead fillings plus install the overflow box on my 125g tank and was hoping you could verify two dimensions for me. The emergency elbow will be set at 7/8" below the top (eurobrace is 3/4") and the overflow box lip @ 1 1/8". The return flow will be about 750 gph and the display is 24" wide. I did a few calculations and am guessing the water level will change 1/8" when the sump pump is running (the sump is next to the display). Also the emergency, siphon and open channel piping are 1 1/4". Thanks, Jim

 

[BeanAnimal]

<a href=showthread.php?s=&postid=13615525#post13615525 target=_blank>Originally posted</a> by jeffrey_ropp
Thanks Bean.

My tank is 48l x 13d x 20t and is constructed using 1/4" acrylic sheets.

If I understand correctly, the slot should be made where the top sheet and back sheet seams come together rather than slightly down in the back sheet itself? I certainly could make it lower without display issues.

As for the existing holes, I took a few shots to further describe my situation. And yes, I'm using my tank as a mini greenhouse.

<table style="width:auto;"><tr><td><a href="http://picasaweb.google.com/lh/photo/F3YqtuStcMzcZWsXc3WQ_w"><img src="http://lh6.ggpht.com/JeffreyRopp/SQKR2MWLm4I/AAAAAAAAB2U/TbK2wBDitgE/s288/Coast%20to%20Coast%20Overflow.jpg" /></a></td></tr><tr><td style="font-family:arial,sans-serif; font-size:11px; text-align:right">From <a href="http://picasaweb.google.com/JeffreyRopp/Collages">Collages</a></td></tr></table>

Thanks again for your help!
Jeff

I am by no means an acrylic expert. If the top is already welded on... then you can but the slot anywhere you like.

 

[BeanAnimal]

You could make the box fit between the holes and use them as closed loop intakes (or the sump return).

You could build the box around the holes and use them the as above, but extend the plumbing through the box (a PITA, but certainly possible).

 

[BeanAnimal]

<a href=showthread.php?s=&postid=13615614#post13615614 target=_blank>Originally posted</a> by shelburn61
ok, I'm guessing the valve to regulate the siphon will be followed by a Tee with a second valve to regulate flow to the skimmer?

Yes that is how the others have done it. Again, I have not tried this, as my skimmer is MUCH too tall to gravity feed.

 

[BeanAnimal]

<a href=showthread.php?s=&postid=13620518#post13620518 target=_blank>Originally posted</a> by jimnrose
Bean, I'm getting ready to drill holes for the bulkhead fillings plus install the overflow box on my 125g tank and was hoping you could verify two dimensions for me. The emergency elbow will be set at 7/8" below the top (eurobrace is 3/4") and the overflow box lip @ 1 1/8". The return flow will be about 750 gph and the display is 24" wide. I did a few calculations and am guessing the water level will change 1/8" when the sump pump is running (the sump is next to the display). Also the emergency, siphon and open channel piping are 1 1/4". Thanks, Jim

1/8" or so sounds about right for 24" and 750 gallons of flow. It may end up being a bit less than that.

7/8" below the brace is also likely just fine.

 

[jimnrose]

Bean, thanks for taking the time to share a great design as well as responding to my questions? I'm not sure I understand your reply (or I didn't ask clearly) so I'll reqord my questions. The emergency elbow would be 1/8" below the eorobrace when the system is running and the overflow box would by 1/4" below the emergency box. I'm guessing the water level will be 1/8" higher when the sump pump is running. Jim

 

[BeanAnimal]

I am still not sure I understand... but I will give it a try.

1/4" is not a lot of wiggle room between the edge of the weir and the eurobrace, but it should work out. If that IS the case, then yes, moving the emergency standpipe entrance up 1/8" of an inch would only leave about 1/8" for the thickness of the water flowing over the wier. You are cutting it close, but it should work. Is that ALL of the room you have to work with?

 

[BeanAnimal]

Photos would also help a lot

 

[jimnrose]

Bean, that's what I have plannned and realize it's easy to alter the height of the emergency standpipe but the weir will be at a fixed height once installed. The only reason I'm going for a tight range is to keep the water level high in the display tank for cosmetic reasons only. I'm in the habit of cutting things close but realize (without experience) the risks are pretty high but the sump return valve could also reduce the flow rate if I'm in dangerous waters.
As for the photos, I'm a retired engiineer who doesn't do anything without detailed drawings but when I retired I also got rid of everything except the computer and keyboard. Some day I might get back in the 'real world' and reactive the printer/fax/scanner.
Again thanks for your support, Jim

 

[GlassReef]

Thought I'd post a couple of pics of my SFOS. I followed Bean's plan exactly, except I raised the open channel pipe about 1/2" above the siphon pipe. I found that the difference in height stabilized the running of the overflow. Pipes are all 1 1/2". Return is driven by Reeflo Dart at approx. 3000 - 3200 GPH.

 

[BeanAnimal]

Yes... raising the open channel pipe forces the siphon to flood before the open channel takes on water.

Wow... GlassReef... I am not sure what to say but nice work!

 

[mflamb]

Approximately what % of the water flows through the open channel?
I'm going to use your system on my new 300, and am considering running the open channel to my fuge.

 

[Sango-chu]

...SOOOOOOO...you mean you raised the upturned elbow 1/2 inch above the other elbow therefore taking in water when the other elbow is already 1/2 submerged...right? PLEASE don't break my heart by telling me that you actually drilled your hole for the drain line 1/2 above the center of all others!!! AHHHHRRRGG..
mine were all drilled on line.....

 

[MeuserReef]

<a href=showthread.php?s=&postid=13691101#post13691101 target=_blank>Originally posted</a> by Sango-chu
...SOOOOOOO...you mean you raised the upturned elbow 1/2 inch above the other elbow therefore taking in water when the other elbow is already 1/2 submerged...right? PLEASE don't break my heart by telling me that you actually drilled your hole for the drain line 1/2 above the center of all others!!! AHHHHRRRGG..
mine were all drilled on line.....

Just put a 1/2" or so piece of PVC into the up-turned elbow to act as a riser tube and you will effectively "raise" the elbow (or at least raise the point where water will make it into the elbow)

No need to go and get heart broken! I believe Bean's original design called for 3 holes, all drilled at the same level. This allows him to use any of the three drain tubes for the siphon (or open channel, or emergency).

Im using this overflow design on my new 120 and I have all 3 holes drilled at the same level. If I need to raise this level, I have quite a bit of 1" PVC laying around to use as a riser tube.

 

[jimnrose]

If it's not practical to raise the open channel pipe, then another option is to cut 1/2" ( or what height is desired) off the open channel elbow.

 

[Scott M]

Hey BeAn, your Inbox is full. I've been trying to PM you to see if you would email me your sketchup files so I can implement them into my own drawings or just send me the valves and bulkheads. I'd appreciate it, thank you.

 

[BeanAnimal]

As others have mentioned, the system will work just fine if the holes and intakes are at the same level. You just can't plunge the siphon standpipe deeply into the sump, or it will have some trouble starting.

Cutting length of the downturned elbow will not help, as the weirs are at the same height