Silent and Failsafe Overflow System

[Lsufan]

How is your overflow setup? Is it a interior box, exterior box or a ghost type overflow? To answer your question, it should be around 1/2” below the water level when the system is running.

From your first post it sounds like u have eighther a ghost type overflow or a exterior box. If that is the case & your stand pipes are actually inside the overflow box then u can try raising the open channel or lowering the syphon. What happens is the open channel can take on to much water & cause it not to build up enough to purge the air from the syphon. By having the open channel higher then the syphon it usually takes care of that.

That is one of the most common reasons but they have others that also make it hard to purge the air from the syphon. If u explain more about your system I’m sure we could figure it out without having to drill holes in the pipe. Drilling a hole can work but if it is setup properly it shouldn’t be needed.

[Chad_P]

Originally Posted by Lsufan

How is your overflow setup? Is it a interior box, exterior box or a ghost type overflow? To answer your question, it should be around 1/2” below the water level when the system is running.

Ghost over flow


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[Chad_P]

Originally Posted by Lsufan

How is your overflow setup? Is it a interior box, exterior box or a ghost type overflow? To answer your question, it should be around 1/2” below the water level when the system is running.

From your first post it sounds like u have eighther a ghost type overflow or a exterior box. If that is the case & your stand pipes are actually inside the overflow box then u can try raising the open channel or lowering the syphon. What happens is the open channel can take on to much water & cause it not to build up enough to purge the air from the syphon. By having the open channel higher then the syphon it usually takes care of that.

That is one of the most common reasons but they have others that also make it hard to purge the air from the syphon. If u explain more about your system I’m sure we could figure it out without having to drill holes in the pipe. Drilling a hole can work but if it is setup properly it shouldn’t be needed.

It’s the eshopps eclipse L overflow. I’ve got the full siphon set up lower than the open channel already, was having issues dialing it in until I did that. I then added the John guest fitting and ro/di line to the top of the open channel and that’s when the system really quieted down and is running awesome. Just can’t seem to get it to purge after restarting return pump.


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[Lsufan]

That is one of the issues with those small overflow boxes. If I was u I would remove the pipe out of the bulkhead on the syphon & try it like that. That will tell u if that is your issue. With that small box u may find the open channel has to be quite a bit higher then the syphon for it to get enough pressure to purge the air. If the open channel starts taking water before the syphon purges the air then it will take a while for it to purge & may not at all.

Remove the pipe from the syphon bulkhead & see. U don’t need a pipe on the syphon anyway, so if it works better u can just put a strainer straight on the bulkhead.

If that doesn’t work then u have narrowed it down & can move on to the next thing to try

[Chad_P]

Originally Posted by Lsufan

That is one of the issues with those small overflow boxes. If I was u I would remove the pipe out of the bulkhead on the syphon & try it like that. That will tell u if that is your issue. With that small box u may find the open channel has to be quite a bit higher then the syphon for it to get enough pressure to purge the air. If the open channel starts taking water before the syphon purges the air then it will take a while for it to purge & may not at all.

Remove the pipe from the syphon bulkhead & see. U don’t need a pipe on the syphon anyway, so if it works better u can just put a strainer straight on the bulkhead.

If that doesn’t work then u have narrowed it down & can move on to the next thing to try

Thanks for the suggestion. I’ll give that a try and report back. Right now I have elbows on the open and siphon channels so I’ll try removing from the siphon


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[Str8linespeed]

Quick question. Getting ready to start up my tank. The hole in the top of the open channel piping elbow. Is it necessary to install a fitting and 1/4" air line? I have not installed that fitting and air line yet, but if I have to where does the air line go to? Is it just an open vent to the atmosphere?

[DougSupreme]

The end of the air line gets mounted just above the running level of the overflow. If there is a blockage in the siphon, the water level in the overflow will rise, closing off the air line turning the open channel into a full siphon

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[Str8linespeed]

Originally Posted by DougSupreme

The end of the air line gets mounted just above the running level of the overflow. If there is a blockage in the siphon, the water level in the overflow will rise, closing off the air line turning the open channel into a full siphon

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Ok, thank you and that makes sense. I guess that brings me to the next question. When I tested my tank the water level was about 3/4-7/8 of the height of my open channel. Full siphon was under the water, and I had about 1" to the top of the emergency drain. Does that sound about right?

[Lsufan]

U really want the end of the airline to be just above the emergency. That way the emergency takes water before the open channel turns to a syphon. The main reason is because if the open channel syphons to quickly it can cause startup issues with the main syphon purging its air. The open channel may drain the overflow box before the syphon can purge its air. So the open channel should only syphon if both the syphon & emergency get clogged, so it’s kind of the last line of defense. It isn’t always the case & there is other factors, but it can be a issue. If I remember correctly u have a mm overflow box. In that case depending on your hieghts, u may be able to get away without a airline. If the hole u drill in the top of the U bend is slightly above the emergency & around 1” below the top of the overflow box then u can get away with not attaching a airline.

As far as water levels, it sounds ok but it’s hard to say without a pic or drawing. U will want the water level to be somewhere on the pass thru bulkhead. If the water level is below the bulkhead u will have a waterfall entering the box & it will be loud. Where u want the water level inside of the box will determine the hieght of the open channel. I would start with the top of the U bend on the open channel close to the top of the bulkheads

[Str8linespeed]

Originally Posted by Lsufan

U really want the end of the airline to be just above the emergency. That way the emergency takes water before the open channel turns to a syphon. The main reason is because if the open channel syphons to quickly it can cause startup issues with the syphon. The open channel drain the overflow box before the syphon can purge its air. So the open channel should only syphon if both the syphon & emergency get clogged, so it’s kind of the last line of defense. It isn’t always the case & there is other factors, but it can be a issue.

As far as water levels, it sounds ok but it’s hard to say without knowing more. Mainly the type of overflow box & how your standpipes are configured. The same thing as far as the easiest way to attach the airline, it depends how your pipes are configured.

Thanks for the explanation.

Im using a modular marine ghost overflow. Tough to get behind the tank to take pics.

0421182017b.jpg

0421182017.jpg

The first pic is full siphon, (90* st. elbow with a strainer),

2nd pic is from the other direction. Its a 1" pipe and a st. elbow and another st. elbow. making the U portion.

[Lsufan]

Yea, I edited my last post because I thought u had a mm box, so it may be worth taking another look at it. I think u can get away with not adding the airline & just leaving the hole in the top of the 90.

If u find that your syphon sucks air every once in a while u may need to add another 90 to make it a U bend. If it doesn’t suck air then it is fine how it is.

[Str8linespeed]

Originally Posted by Lsufan

Yea, I edited my last post because I thought u had a mm box, so it may be worth taking another look at it. I think u can get away with not adding the airline & just leaving the hole in the top of the 90.

If u find that your syphon sucks air every once in a while u may need to add another 90 to make it a U bend. If it doesn’t suck air then it is fine how it is.

Thanks for the info, I'll hopefully be starting it up today.

[Str8linespeed]

Tank is online and I believe I have the BA for the most part dialed with the current piping in the overflow.

I have 2 questions.

1) My water level is about 1.25-1.5" below the rim of the tank. Just about a 1/4" above the lowest point of the slots in the weir. I have at least a full inch left until it dumps over the top of the weir. If I want to raise the water level in the DT, would I cut a longer piece of PVC to raise the open channel u bend higher in the overflow box, as well as raise my emergency?

2) Im not even close to going over the top of my emergency drain, but occasionally I will get a trickle of water that comes down that pipe. This happens about once every 45min. I've taken the pipe out of the overflow box, and twisted it back in but it still happens. Should I be concerned?

[Lsufan]

1- The water level in the dt is determined by the hieght of the weir. So there is no way to adjust that. By adjusting the valve on the syphon it will only affect the water level inside of the overflow box, not the DT.

2- It will probably make some noise every time water goes into the emergency. I would try to lower the water level inside of the overflow box. If a little water goes into the emergency on startup it isn’t a big deal & can even be expected, but I wouldn’t want it happening under normal conditions when the system is running. Where is the water level inside of the overflow box? How high is it on the pass thru bulkheads that hold the box on the tank?

[Str8linespeed]

Originally Posted by Lsufan

1- The water level in the dt is determined by the hieght of the weir. So there is no way to adjust that. By adjusting the valve on the syphon it will only affect the water level inside of the overflow box, not the DT.

2- It will probably make some noise every time water goes into the emergency. I would try to lower the water level inside of the overflow box. If a little water goes into the emergency on startup it isn’t a big deal & can even be expected, but I wouldn’t want it happening under normal conditions when the system is running. Where is the water level inside of the overflow box? How high is it on the pass thru bulkheads that hold the box on the tank?

1)Gotcha, not much I can do about that, and the weir is as high as it could go anyways.

2)The water in the overflow isnt going high enough to get into the emergency tube, I think its going between the bulkhead fitting and pvc pipe. I still have about 2" until it gets to that height. Like I said its just a dribble of water coming out of that tube, about every 45 minutes or so. The water height on the pass through bulkheads are about 1/2 of the diameter. Kind of hard to tell, because I cant get my head back there.

[Lsufan]

That isn’t anything to worry about then. A little water getting through won’t hurt anything & u shouldn’t be able to hear it. Seems about right on the water level to, so it sounds like u have it dialed in pretty good.

[Sisterlimonpot]

Without combing through all these posts, can someone give me the measurement of the distance from the back of the tank to the most end point of the plumbing that extrudes out from the three 1.5" standpipes?

i'm planning the traditional layout from the tank, drill a hole, place a 1.5" threaded bulkhead, Immediately a "T", plumbing goes straight down with 45 degree bend so that the gate valve/ball valves will be plumbed under the tank.

Depending on the answer, I may want to drop down to 1.25". Would that be advisable for a 300 gallon tank?

[Lsufan]

U are looking at 5.5” to 6” using a common bulkhead if u use a slip bulkhead & not a threaded on the nutt side of the bulkhead. If u use a threaded u will have to use threaded coupling to connect the bulkhead to the tee, & that will add another 1” to 2” depending on the coupling u use. By using a slip bulkhead on the nutt side of the bulkhead u can get the tee to where it is all the way against the bulkhead.

They also sell short bulkheads that can save about 1” in space behind the tank. So if u use a short, slip bulkhead u can only extrude 4.5” to 5” from the back of the tank. Most regular 1.5” bulkheads stick out 2” from the back of the tank. The short ones only stick out 1”.

So in 1.5” u are looking at
1- regular size slip bulkhead 5.5” to 6”
2- regular sized threaded bulkhead. 6.5” to 7.5”
3- short bulkhead(which I believe are all slip on the nutt side) 4.5” to 5”

[Sisterlimonpot]

Lsufan,
Thank you, that's exactly the information was looking for.

[tydtran]

Why do we need all these elbows?

I am planning to use Modular Marine overflow for my next tank. I look at how people plumb the external boxes and see that people use a down turn elbow for the full siphon and a slightly higher down turn elbow for the open channel. Why?

Wouldn't it more practical to use a short straight pipe for the full siphon, a longer straight pipe for the open channel, and the longest straight pipe for the emergency drain?

This would make installation easier and being able to see into the open channel allows you to adjust the water level in the box to a thin laminar flow easily.

[Lsufan]

As far as the syphon, if u extend a pipe out of the bulkhead & don’t have any 90’s then it can make sort of a vortex & suck air every once in a while. Especially with the smaller exterior boxes that most people get with the ghost type overflows. If u wanted to go that route I would just skip the pipe completely & put a strainer straight on the bulkhead. Doing it that way it will more then likely be low enough in the box so it won’t suck any air.

As far as the open channel, it would make more noise if u leavebit open on the top & would be loud if u have much flow at all going through it. One of the purposes of the open channel is so the system remains quiet with a little flunctuation in the system. With a open pipe u may be able to get it dialed in to where it may be quiet, but any flunctuation it would get loud & u would have to adjust the valve. One of beans goals when he came up with the setup was to pretty much have a system u can set & forget. So not have to constantly be adjusting the valve. Plumbing size makes a difference but I havnt touched the valve on eighther of my setups in years.

So imo, u could get by with just a pipe on the emergency, just a strainer straight on the bulkhead for the syphon, but I would make the U bend for the open channel. With a MM box u can probably get by without using the airline & just drill a hole in the top of the U bend, but u would need to set the hieght of the standpipes at the right level

[tydtran]

Thanks for the explanation Lsufan. I will do as you sugges.

[homerjay]

I'm building a 2ft cube and I'd like to put an internal Calflo with beananimal plumbing. I will be moving about 500gph return. I have a few questions.
1. How deep and wide do you recommend the dimensions of the overflow be to accommodate the siphon.
2. What size pipe do you recommend for a small application like this?

[Lsufan]

I would use 1” plumbing & 1” bulkheads for the drains. For the return it will depend on your return pump & if u plan on using locline. I would more then likely just use 1” for the returns to keep all the plumbing the same. If u want to use locline I would get a threaded 3/4” bulkhead for the return & reduce down from 1” to 3/4” close to the bulkhead.


As far as size, u just have to be able to fit the plumbing. So for 1” plumbing u will need to make the box atleast 2.75” wide (front to back) to be able to fit a street elbow inside of the box. Different fittings are a little different in size, so u may want to buy the plumbing so u can measure it before making the box. Or u could go ahead & make the box 3” & u will be able to fit the elbow. If u want the box a little narrower then u can always cut a little off the spigot end of a street elbow. I made my box 2.75” & from what I remember I had to cut about 1/4” off the elbow so it would fit.

As far as height, it will depend where u drill the holes in the tank. When u drill a hole u need to stay 1X the hole diameter from the edge of the glass to the hole. So for a 1” bulkhead u will need to be a minimum of 1.75” from the top rim of the tank to the top of the hole. If u go with these dimensions u should be able to make the height of the box 4”. That will put the top of the overflow box about 1.5” from the top of the tank, which is where your water line will be. So assuming u use a 1” bulkhead & u drill the hole 1.75” from the top of the tank to the top of the hole u can make the box 3” wide & 4” tall if u want the water line to be 1.25” to 1.5” from the top rim of the tank. If u want the water level higher then u will need to make the box taller

[saf1]

Sort of a dumb question but what prevents the valve from being fully open on the primary drain? My overflow drains are drilled 1 1/2" so that is the pipe size I am using along with the valves. However, inside the overflow box I didn't have room for it so reduced it to 1" pipe similarly to what Bean did in his. If mine is fully open then it starts to make the sucking sound. Hard to say how much but I have my valve probably 1/4 turn or reduced.

Does this indicate that my pump is not able to keep up? Cor 15 is what I'm running on a 210 gallon tank. Figured I'd ask since I wasn't sure. Thanks - have a good day.