Silent and Failsafe Overflow System

[cichlidtx]

uncleot6, thanks for the response. The bulkheads are slip/slip. Where should I put the ball valve on the siphon? I've seen some just below the sanitary tee and others just above the sump. Thanks again, I want to make sure I get it right.

[uncleof6]

Put it where ever it is easiest to get too. The only time it makes a difference is in the case of a long drop, into a basement, in which case you would want the valve down by the sump. Otherwise it doesn't matter.

[reev]

cichlidtx, I did a similar setup with the overflow box inside on my 50G about 2 years back. Soon after I finished I realized that I don't like it much because the box was taking a good amount of space inside the tank. I think it was about 3-4" wide to allow for the elbows and bulkheads to fit in.

Since then I did 2 other setups using this method for a friend of mine and for my new 125G, and in both I used a thin overflow/weir box on the inside (1" wide or so) and the wider overflow box with the elbows and pipes on the outside. # hose have been drilled in the tanks to allow the water to flow from inside the weir into the overflow box.

I also setup the siphon and the open pipes on each side of the overflow box with the elbows pointing down and parallel with the back wall of the tank. The emergency pipe is under the overflow box coming up through a bulkhead and then a straight pipe. This allowed me to make the outside overflow box a bit thinner and not need extra space for the pipes behind the tank.

HTH

[afgun]

Had I to do mine over again, I'd do it that way or instead of a weir in the tank, slot the glass.

[reev]

Originally Posted by afgun

Had I to do mine over again, I'd do it that way or instead of a weir in the tank, slot the glass.

Ops. It seems that I used the wrong term.
If "weir" means the overflow box can siphon water over the tank wall, it is NOt what i meant .

I meant that I had built a very thin overflow box that sits inside the tank and covers the 3 holes i made in the back glass allowing only the surface water to go inside the box and in those holes. On the outside there is the full size overflow box with the pipes and the elbows.

Sorry for confusion.

[BeanAnimal]

reev,

In this context, the "weir" is whatever the water flows over to reach the standpipes. That is the box wall, the lower edge of a slot in the glass that feeds an external box, etc.

[JTL]

I am still having trouble getting the full siphon to start when I restart the pump. I thought it may be an air leak but I think I ruled that out. The gate valve is restricting the flow to the point that the 1 1/4 returns will not start a siphon when they are set to match my flow. The emergency return works like it should. I am using an Eheim 1262 as a return pump. Any suggestions short of getting a return pump with more flow.

[RocketSurgeon]

Originally Posted by JTL

I am still having trouble getting the full siphon to start when I restart the pump. I thought it may be an air leak but I think I ruled that out. The gate valve is restricting the flow to the point that the 1 1/4 returns will not start a siphon when they are set to match my flow. The emergency return works like it should. I am using an Eheim 1262 as a return pump. Any suggestions short of getting a return pump with more flow.

A larger return pump allows for a quicker siphon start, but if it is not starting the siphon all together, a larger pump will not fix that problem, I wouldn't think.

[RocketSurgeon]

Originally Posted by cichlidtx

uncleot6, thanks for the response. The bulkheads are slip/slip. Where should I put the ball valve on the siphon? I've seen some just below the sanitary tee and others just above the sump. Thanks again, I want to make sure I get it right.

I'm moving mine farther down from the t, and I'm swapping it out with a gate valve. the ball valve is too hard to make minuscule adjustments.

[teesquare]

Just a thought Rocket Surgeon....I like having a ball valve for the rare need off a quick, and easy "on or off"...
I would not remove the ball valve, but adding the gate valve could be of benefit ( tho I have not needed one to balance quiet flow, I can see where it may be useful)
T

[JTL]

Originally Posted by RocketSurgeon

A larger return pump allows for a quicker siphon start, but if it is not starting the siphon all together, a larger pump will not fix that problem, I wouldn't think.

That makes sense but I wonder why the syphon works when the gate valve is wide open and not otherwise. There must be a logical solution since so many people are using this system successfully. Mine is sort of useless at this point.

[teesquare]

Some pictures would really be helpful in diagnosing where the problem is.
T

[JTL]

It is just a Beananimal set up with (3) 1 1/4 return pipes with three 90 degree turns, the primary one has a gate valve the other two do not.

[teesquare]

It sounds straight forward enough - but I cannot over emphasize the help that pictures may be to everyone here - in an effort to assist you in solving the problem.

T

[reev]

Originally Posted by JTL

That makes sense but I wonder why the syphon works when the gate valve is wide open and not otherwise. There must be a logical solution since so many people are using this system successfully. Mine is sort of useless at this point.

Initially, I had a similar problem on my latest overflow. I fixed it by making sure that the siphon pipe is barely under the sump water surface during normal operation and by extending the open channel pipe to be about 4-5" under the sump water level. I believe I saw BeanAimal recommending that to a bunch of "pages ago .

[uncleof6]

Originally Posted by reev

Initially, I had a similar problem on my latest overflow. I fixed it by making sure that the siphon pipe is barely under the sump water surface during normal operation and by extending the open channel pipe to be about 4-5" under the sump water level. I believe I saw BeanAimal recommending that to a bunch of "pages ago .

I'll have to take your word for that... i have not seen that recommended. The one recommendation I have seen is raising the open channel intake a half inch or so above the siphon intake.

[teesquare]

Yeah...I don't remember that recommendation either....Seems that by extending the pipe further below the surface of the water, you actually increase the resistance to purge air from it on re-start.....which would potentially over-burden the main siphon, causing the emergency drain to kick in....?
T

[JTL]

Simple solution. I raised the open channel which upon inspection was WAY to low, then I noticed the airline tube for the emergency drain was too low as well. The combination did not give the main drain sufficent time to establish a siphon. Thanks Jim and T!

[teesquare]

Most welcome JTL!

Best of Luck!

T

[TheFishMan65]

JTL - Airline tube for the emergency drain???? Did you mean open?

[JTL]

Originally Posted by TheFishMan65

JTL - Airline tube for the emergency drain???? Did you mean open?

Nope, as I understand it. The open drain is just that, open. The emergency drain is a full siphon that kicks in when the airline tube can no longer get air.

[uncleof6]

Originally Posted by JTL

Nope, as I understand it. The open drain is just that, open. The emergency drain is a full siphon that kicks in when the airline tube can no longer get air.

Hummm, alrighty then. But why you gotta do this when I only got one hand to type?


You have three standpipes. A siphon, sealed w/valve to adjust water height in over flow. Open channel is a durso type standpipe.. with an airline looped back into the overflow. The third standpipe is the dry emergency, that is the one with the upturned elbow.

Now that the nomenclature is straightened out let's try this again.

[JTL]

I stand corrected, but someone needs to change the nomenclature to suit my definitions. What I did is raise the "dry emergency" because it wasn't so dry but it was open and raised the airline tube on the "open channel" which is probably about the same as raising the intake since it raises the full siphon water level. Anyway is appears to work and I appreciate the help.

[BeanAnimal]

The emergency drain has no air intake, it is set higher than the other two standpipes and will kick in when the water level is too high. It is dry otherwise.

The open channel standpipe is the one with the air intake. The intake is set so that the open channel becomes a siphon in the event that system becomes unbalanced. This allows the open channel standpipe to operate silently during normal circumstances but become a full siphon (thus flushing the overflow box) during abnormal operation and/or system startup.

The emergency standpipe is the fail-safe. Systems with low flow may never see it kick in, even with a fully plugged siphon and partialy blocked open channel. However, those with high flow systems may see it kick in even during system startup.

Again (for those who did not read the thread or my website) the reason for the 3rd standpipe is for fail-safe operation in ANY environment. The system was published as a simple one-size-almost-fits-all solution. The goal was to publish a simple design that could be easily leveraged to any size tank and therefore be easily supported, explained and passed along. This was chosen over publishing 2 or 3 different standpipe topologies and confusing "flow rate" guidelines that do nothing but make things far more confusing and create a vastly larger number of questions.

This setup greatly differs from typical standpipe configurations, be they "durso" or "herbie" style setups. The fail-safe air intake and fail-safe dry standpipe virtually eliminate the possibility of system overflow. At the same time, the useable range of flow rates, ease of system adjustment, self tuning and stability is a vast improvement over other designs. While some aquarists may not need or desire the benefits of the system, they were a MUST HAVE for me.

[BeanAnimal]

Originally Posted by JTL

I stand corrected, but someone needs to change the nomenclature to suit my definitions. What I did is raise the "dry emergency" because it wasn't so dry but it was open and raised the airline tube on the "open channel" which is probably about the same as raising the intake since it raises the full siphon water level. Anyway is appears to work and I appreciate the help.

Raising the air intake and raising the weir height are two different things.

Raising the weir height of the open channel in relation to that of the siphon standpipe forces water into the siphon standpipe before it gets to the open chennel. This can aid in forcing the siphon to start, but in most cases is not needed if the standpipes are terminated properly just below the working water level of the sump.

Raising the air intake simply changes the "fail-safe" level in which the open channel standpipe turns into a full siphon. The air intake needs to be set above the normal operating level of the overflow box but below the point where the system will flood the floor. If it is kicking in before the siphon takes hold, and preventing the siphon from ever reaching a balance, then it is too low