Silent and Failsafe Overflow System

[MidwesternTexan]

These comments about filter socks, fish, purging, etc.

1st- unless the gate valve in the system is open pretty widely to achieve FS- medium/larger fish could make it down the pipe, and get caught on the valve.
If not caught, they make it to the sump, and/or a filter sock next.
It's imperative to have grating on your tank's skimming overflow so that they dont get in there anyways.
But yes, they often do anyways.

If you're running a filter sock:
I run a sock on my FS intermittently.- But's in the larger 6 or 7" opening on top.
It sits in the sump about 3/4 down, so it keeps some water in it.
I've actually had a fish rescued after a few days from this sock set up.

Purging with or without a sock?
IIRC- the distal/sump end of the FS should be just slightly under water- which should remain constant height in a section as in the skimmer section.

The air would purge whether or not a sock is on there, especially they way I use a larger sock that is open around the pipe on top.
I fact, even a snugger fitting sock shoule still purge air- I dunno

What am I missing here?

 

[Rumjahn]

Synergy Reef (aka Ghost) Overflow

Synergy Reef (aka Ghost) Overflow

BeAn,

Thank you for sharing your knowledge and insight with this clever system. I have the Synergy Reef overflow, which says right on their website that your system works with it, but I could not find clear instructions on how to make it happen. I thought I'd share my experience with adapting your system to the external overflow, so others can benefit. I have achieved complete silence with 1" pipes running at 600 gph.

Here is a link to the overflow: http://synergyreef.com/product/16-synergy-reef-overflow/

This is the piping configuration I used inside the box:

From left to right: open channel, emergency standpipe, siphon.

The open channel has a 1/4" hole drilled right into the top of the elbow. I eliminated the air line, because I wanted to be able to close the lid on the box. The water level bisects the horizontal section of the open channel, so it is below the air hole and the emergency standpipe, but completely submerges the siphon. Here is a view from the top, with the system running so you can see the water level:

You can tell from this view that the siphon is completely submerged, and the open channel is not. This is important, keeping the air hole above water level under normal conditions.

External plumbing from the box:

And finally, where the drains exit into the sump:

In this picture, the system is running at full 600 gph. And you can see there are NO bubbles coming from any drain. It is silent, as designed! It also passed all the tests. All the drains are 1", but a single 1" drain running at full siphon can easily accommodate the 600 gph of flow I'm putting through it. When I close off the full siphon, the water level rises until it covers the hole in the OC. A little bit goes into the emergency standpipe, but then the OC converts to full siphon and level immediately drops to the level of the air hole. Once air starts being sucked in, it reaches an equilibrium at the level of the air hole, making a gurgling/sucking sound. That would be my audible alarm that the full siphon is clogged!

The same goes for if the OC were clogged, except the gurgling would come from the emergency standpipe.

Another thing to note is that even though the siphon exits several inches under the water level of the sump, there are no problems with stopping and restarting the flow. I think enough water is retained in the siphon to purge the air. I did notice that when I started the system from completely dry, the siphon wouldn't start until I closed off the OC with my hand, thereby letting all the air purge through the siphon. If I have problems with that in the future, I can simply cut the siphon a little shorter in the sump.

So that's my experience with your system and the Synergy Reef or Ghost overflow. I hope this little write-up helps someone else as your system has helped me. Thanks again!

 

[jason2459]

Looks like how I have my overflow setup in the back of the tank. I would get a right angle JG fitting for that hole on the open channel and get an air line back in it. Or at least test to make sure it kicks in properly and maintains a siphon if you close off your current siphon. Always test all failure scenarios.

I would also go ahead and trim the open and full siphon pipes in the sump area. You should not have to manually do anything at any time to get the siphon going.

But that's just me and my 2 cents.

 

[Floyd R Turbo]

Drain valve needs to be at the bottom of the pips as close to the drain exit point as possible, not up high. You will have extended purging times by placing it high

And finally, where the drains exit into the sump:

Remove pipe extensions in the sump. All drains should terminate <1" below the operational water line. Otherwise you will get air trapped in the line that will extend the startup purge or prevent it all together. Also this will inhibit failsafe operation

 

[Rumjahn]

Looks like how I have my overflow setup in the back of the tank. I would get a right angle JG fitting for that hole on the open channel and get an air line back in it. Or at least test to make sure it kicks in properly and maintains a siphon if you close off your current siphon. Always test all failure scenarios.

I would also go ahead and trim the open and full siphon pipes in the sump area. You should not have to manually do anything at any time to get the siphon going.

But that's just me and my 2 cents.

Jason,
No air line is necessary, the system has been tested for complete loss of the siphon drain, and the OC works as it should. Also, no manual adjustment is necessary on restart. I only had to do that one time, when the pipes were first installed, but every other time since then, when I shut it off and restart the siphon purges itself within 30 seconds or less:

It also passed all the tests. All the drains are 1", but a single 1" drain running at full siphon can easily accommodate the 600 gph of flow I'm putting through it. When I close off the full siphon, the water level rises until it covers the hole in the OC. A little bit goes into the emergency standpipe, but then the OC converts to full siphon and level immediately drops to the level of the air hole. Once air starts being sucked in, it reaches an equilibrium at the level of the air hole, making a gurgling/sucking sound. That would be my audible alarm that the full siphon is clogged!

The same goes for if the OC were clogged, except the gurgling would come from the emergency standpipe.

Another thing to note is that even though the siphon exits several inches under the water level of the sump, there are no problems with stopping and restarting the flow. I think enough water is retained in the siphon to purge the air. I did notice that when I started the system from completely dry, the siphon wouldn't start until I closed off the OC with my hand, thereby letting all the air purge through the siphon. If I have problems with that in the future, I can simply cut the siphon a little shorter in the sump.

Drain valve needs to be at the bottom of the pips as close to the drain exit point as possible, not up high. You will have extended purging times by placing it high


Remove pipe extensions in the sump. All drains should terminate <1" below the operational water line. Otherwise you will get air trapped in the line that will extend the startup purge or prevent it all together. Also this will inhibit failsafe operation

Floyd,

See comments above. I like the drain valve where it is, because I can reach it by standing next to the tank instead of crouching down and reaching into the cabinet. Purge time is <30 seconds, so I'm happy. How does having lower drain terminations inhibit failsafe operation? That part I don't understand.

 

[Floyd R Turbo]

The air cannot properly escape from the pipes fast enough to respond. If something clogs the siphon line, and the water level rises in the box, the OC should kick over to siphon but if this doesn't happen quickly, you are relying on the emergency drain to take the excess. I guess the answer is do a bunch of worst-case testing and make sure that the system works as it should.

For any siphon line system where the pipe must purge out the air, the lower you place the drain line under the water surface, the harder it is for all of the air to get purged out. You only need the bottom of the pipe to be 1/2" below the surface. I've got a system running 300 GPH on a 1.5" line and it's maybe 1/4" or 1/2" under the surface. there just is no need to sink the pipe down that far, it can only cause problems and provides no benefit.

 

[Rumjahn]

The air cannot properly escape from the pipes fast enough to respond. If something clogs the siphon line, and the water level rises in the box, the OC should kick over to siphon but if this doesn't happen quickly, you are relying on the emergency drain to take the excess. I guess the answer is do a bunch of worst-case testing and make sure that the system works as it should.

For any siphon line system where the pipe must purge out the air, the lower you place the drain line under the water surface, the harder it is for all of the air to get purged out. You only need the bottom of the pipe to be 1/2" below the surface. I've got a system running 300 GPH on a 1.5" line and it's maybe 1/4" or 1/2" under the surface. there just is no need to sink the pipe down that far, it can only cause problems and provides no benefit.

I understand that you only need the drain to be barely submerged. But I've also tested my system the way it is. When it is running at full tilt, I shut off the siphon line by slamming the valve shut (simulating immediate and complete occlusion of the siphon by any foreign object). The water in the box immediately rises, closes off the air hole on top of the OC, and that immediately converts over to full siphon. A few bubbles purge out the drain of the OC, and water level in the overflow quickly drops. Not a drop is spilled. A little bit trickles into the emergency standpipe before the OC achieves full siphon, but since full siphon is achieved in the OC within seconds, the emergency doesn't even really come into play.

What you say is true in theory, and important to understand if someone is troubleshooting issues. However, my system has been tested and proven to work, which I think is good information as well. The drains don't NEED to be that deep, but I'm adding a data point to the knowledge base that if for whatever reason you want the drains lower, it's possible for the system to still work. Perhaps someone is using a sump design that requires lower drain exits, or they have fluctuating water levels where they want a margin of greater than 1/4" to 1/2". They might find this information useful.

 

[jason2459]

I would cut the drains entering into the sump so they are not submerged as much. That is all.

 

[Rumjahn]

Okay, sheesh, I'll shorten the damn drains!

 

[Floyd R Turbo]

For a higher-flow system, the drains will probably purge out the air a lot more efficiently, so this is why this is working for you. Good to hear that you tested it, that is important, so that being said you could probably leave the drain extensions in there if they are a total pain to remove. You might find that over time, as material build up in the pipes, it might start acting slightly differently. That may or may not affect start-up and failsafe operation, probably not.

If you were running a more moderate flow system, where there wasn't nearly as much flow through the pipes (i.e. you were mainly using the BA system for fail-safe and not necessarily for high-volume) then your startup could definitely be an issue. This is obviously not the case for your setup.

 

[jason2459]

I believe if someone has to do anything at all special to get it started up even the first time then something is not setup right and can pose issues in the future. The most obvious in what we can see is the depth of the pipes in the sump.

 

[Floyd R Turbo]

But as he mentioned, he doesn't have to do anything special to get it to start up...or did I miss something?

 

[jason2459]

But as he mentioned, he doesn't have to do anything special to get it to start up...or did I miss something?

I did notice that when I started the system from completely dry, the siphon wouldn't start until I closed off the OC with my hand, thereby letting all the air purge through the siphon. If I have problems with that in the future, I can simply cut the siphon a little shorter in the sump.

 

[Floyd R Turbo]

Oh, I missed that. Yes, the pipe extensions are likely the cause of this. Removing them is one option, the other is to drill a very small hole just under the waterline to allow air to escape from the pipe, but then you have to keep the hole clear, another maintenance thing...

 

[Rumjahn]

I agree with you guys, the easiest way is to shorten the drains, and that will only take me 2 minutes to do.

As I also stated in my original post, I only had to occlude the OC to get the siphon started one time, on initial startup, when the pipes were completely dry. Since then, I've shut off and restarted the system multiple times, without any failure of the siphon restarting itself. I think enough water is retained in the siphon to restart it, even with the low drains.

Raising the drains, however, will give me more margin of error as jason says, so that's what I'll do.

 

[Jlentz]

I'm assuming those are bulkhead sizes, not hole sizes.



3"4" is too small imo. I suppose it could be done, but I've never seen it done. 1" drains is as small as I would go.



If anything, the 1" drain for full siphon - but then the system is beginning to become unsafe.

Yeah... 3/4". LFS plumbing guru suggested just going herbie with the 1-1/4" being the siphon. I'm paranoid though.

Is there a reason it wouldn't work with the 3/4" siphon and 3/4" open channel? I'm thinking it would be best for the emergency to be the big pipe.

 

[shiftline]

How many gate valves are required? I see multiples in most pics but would you just need one?

 

[Spar]

How many gate valves are required? I see multiples in most pics but would you just need one?

Just one is needed, for the full siphon. That is the only one you will be adjusting in fine detail.

The other two you will have either fully open at all times (during normal operation) or fully closed (during maintenance). Thus just a simple ball valve will suffice.

 

[shiftline]

Thanks for clarifying. Why do you need to close it for maintenance? Wouldn't simply tuning off the return pump drain the lines?

 

[Spar]

Thanks for clarifying. Why do you need to close it for maintenance? Wouldn't simply tuning off the return pump drain the lines?

If you want to do it that way, solely, then I suppose the ball valves aren't necessary.

You can always add them on later if you decide it beneficial.