I am trying to sift through all of this info, but basically I am trying to drill my 72g bowfront and want to know what dimensions should the holes be drilled? The bulkhead will need some space next to the plastic trim so should I try to make these as high as I can and how far apart should I drill these three?
Silent and Failsafe Overflow System
- Thread starter JohnL
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uncleof6
Active member
1 - 1.5x the hole diameter, from the top edge of the GLASS, and 1 - 1.5x the hole diameter, from other holes. These are the minimum clearances required. There is more to think about than that, however. It is the size of the pipe, that will ultimately determine where the holes actually are, in relation to the top of the tank, and the bottom of the overflow. Very generally speaking, you want the bottom of the down turned elbows ~ 1" off the floor of the overflow. (assuming a shallow overflow box) , and the upturned elbow ABOVE the operating water level. A few measurements, a little addition and subtraction, will tell you where to center the holes.
Jim
Thanks uncleof6, I am going to be using 1" piping using street elbows so thats my determining step of where those land, I was trying to see if the tree holes would be in the same line or if they were going to be off the center line...
Don't know if someone had figured this one out already
Don't know if someone had figured this one out already
uncleof6
Active member
I run them all on the same center line. Some raise the open channel a half inch or so to facilitate starting the siphon (higher head pressure on the siphon.) If you follow the design criteria for the system, there should not be a problem starting the siphon, however.
Jim
Jim
coralcruze
New member
I'm doing just that... However, I would not say that my tank is a conventional one. It is fully custom. if interested I posted pictures in the post a few pages back. take a look...
coralcruze
New member
Hey bean...
I wanted to personally THANK YOU and all the others who have contributed to this thread. as I mentioned I plumbed the tank and tested it all out. I am amazed that I did not have to do a thing to tweak anything. It all worked perfectly just as designed... THE FIRST TIME. Perhaps begginers luck? Now I know what you meant when you said that its one of those things that you just have to build to fully understand and appreciate. what a great system.
anyone out there considering doing this, don't hessitate... do it. You wont regret it.
I wanted to personally THANK YOU and all the others who have contributed to this thread. as I mentioned I plumbed the tank and tested it all out. I am amazed that I did not have to do a thing to tweak anything. It all worked perfectly just as designed... THE FIRST TIME. Perhaps begginers luck? Now I know what you meant when you said that its one of those things that you just have to build to fully understand and appreciate. what a great system.
anyone out there considering doing this, don't hessitate... do it. You wont regret it.
coralcruze
New member
have a question. over time as filamentatious algae builds up on the inside of the pipe, has anyone here had to adjust the flow through the full siphon line at all?
You should not have filamentous algae in the siphon -unless you have a high organics load. That may require other fixes.:lol2:
And if that became a problem - any algaes that require light should only be growing near the entrance of the plumbing, so thay should be accessible.
Again - because I siliconed my fittings (inside the overflow box) - rather than gluing them - I can remove/repace anything. No problem.
T
And if that became a problem - any algaes that require light should only be growing near the entrance of the plumbing, so thay should be accessible.
Again - because I siliconed my fittings (inside the overflow box) - rather than gluing them - I can remove/repace anything. No problem.
T
coralcruze
New member
OK, I may have mistated when I said filamentatious algae. what I meant was crustations... Not sure how long you have been in this hobby but my overflow off of my last tank is 15 years old and I can tell you that 1/3 of the inside of the pipe was covered by crustations growing in it.
Lets face it... none of us ever go under the tank once its set up to disassemble the standpipe and clean it, unless of course there is a problem. at least I never did this on my last tank. I plan on doing so on this one but only because its much easier to get at. HOWEVER, I don't like your idea of using silicone to GLUE plumbing lines. silicone is a sealant its not designed to be a glue. but thats just me to each his own. I kind of like beans statement. PVC was designed to be welded so just weld it and be done with it! :spin3:
BeanAnimal
Premium Member
That is why I incorporated cleanout caps into the standpipes
Just so there is no confusion, Teesquare does solvent weld his external fittings. He used silicone on the internal elbows (inside the overflow box) so that there was no chance of the siphon elbow sucking air.
Thanks for clarifying Bean!
Coral- I really do not think you will have a build up problem, unless you are using an abundant amount of kalkwasser, and calcium based additives - or - if your nutrient load is too high.
If you have a high nutrient load, you will get a lot of the small hard tube fan worms, and other crustaceans. If you lower the nutrient load on the system - they will die back.
If you reduce - or rather - change the method of administering the calcium to the sytem - you will not have the problem of build-up in the pipes.
Finally, that is why I like the silicone - again - INSIDE the overflow box....It gives me the opportunity to "fix" whatever situation I could need to deal with.
We all have our favorite ways of doing things, and I appreciate that you too are well experienced in knowing that ultimately, none of us have a 100% surety that our tanks will be "perfect".
That is why I love the BeanAnimal overflow. It has prevented a lot of embarrassment with the Mrs...(no wet floor and no noise!)
Coral- I really do not think you will have a build up problem, unless you are using an abundant amount of kalkwasser, and calcium based additives - or - if your nutrient load is too high.
If you have a high nutrient load, you will get a lot of the small hard tube fan worms, and other crustaceans. If you lower the nutrient load on the system - they will die back.
If you reduce - or rather - change the method of administering the calcium to the sytem - you will not have the problem of build-up in the pipes.
Finally, that is why I like the silicone - again - INSIDE the overflow box....It gives me the opportunity to "fix" whatever situation I could need to deal with.
We all have our favorite ways of doing things, and I appreciate that you too are well experienced in knowing that ultimately, none of us have a 100% surety that our tanks will be "perfect".
That is why I love the BeanAnimal overflow. It has prevented a lot of embarrassment with the Mrs...(no wet floor and no noise!)
I've been through all of the posts at one time or another, so I hope I'm not asking what's been covered before, but I think I see a possible way to simplify part of the implementation when using an skim-over-the-side into an external overflow box. For the primary siphon drain, as it's the head in the box and the throttling valve on this drain that result in this drain starting to operate as a siphon, isn't the 180 loop on top redundant? Couldn't its opening be a simple open tube, opening lower than the 2nd "open/to-siphon" drain? Wouldn't it fill up with water (as usual, due to the valve), lose the bubbles and the weight of the water kick-in the high rate of flow? (with the usual adjustment such that the excess return flow goes through the second drain as an open drain)
BeanAnimal
Premium Member
I am having a bit of trouble following your post... but I will try to respond. I think you may have missed the purpose of the air intake tube and the functions of the different standpipes.
There is no air intake on the siphon standpipe. The open channel standpipe has an air intake to prevent it from siphoning. The "180 loop" is not redundant, it is what allows the air in, but also allows the intake to become submerged and turn the standpipe into a full siphon in the event of high water.
In some configurations, it is possible that the air intake could be a simple hole or short vertical tube on top of the open channel standpipe. This would depend on the other parameters of the setup (overflow box depth, intake pipe design, critical flow depth, etc.)
There is no air intake on the siphon standpipe. The open channel standpipe has an air intake to prevent it from siphoning. The "180 loop" is not redundant, it is what allows the air in, but also allows the intake to become submerged and turn the standpipe into a full siphon in the event of high water.
In some configurations, it is possible that the air intake could be a simple hole or short vertical tube on top of the open channel standpipe. This would depend on the other parameters of the setup (overflow box depth, intake pipe design, critical flow depth, etc.)
coralcruze
New member
hey bean, again I just wanted to say thanks for all of your efforts with this thread. I am very happy with the system. it is dead silent and very predictable and no fluctuations with the water level in the overflow trays.
You may recall That I was using 1" stockman style standpipes and instead of an airline loop on the failsafe line I drilled a hole in the side of the pipe on top. I ran a test simulating a clogged full siphon line and what I found is that it takes the system too long for the failsafe line to turn into a full siphon and the trays overflow. I can't lower the pipes further than what I already did. Do you have any other suggestion that I can try? do you think having a small airline coming out of the horizontal hole and pointing straight down would achieve a full siphon quicker? Let me know if you need me to take a few pics for clarification? thanks again.
Oh and just to report on the threaded connections... I did not have any issues with leaking at all. I did use some putty though just in case.
You may recall That I was using 1" stockman style standpipes and instead of an airline loop on the failsafe line I drilled a hole in the side of the pipe on top. I ran a test simulating a clogged full siphon line and what I found is that it takes the system too long for the failsafe line to turn into a full siphon and the trays overflow. I can't lower the pipes further than what I already did. Do you have any other suggestion that I can try? do you think having a small airline coming out of the horizontal hole and pointing straight down would achieve a full siphon quicker? Let me know if you need me to take a few pics for clarification? thanks again.
Oh and just to report on the threaded connections... I did not have any issues with leaking at all. I did use some putty though just in case.
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thanks for your response
I understand well the three pipes and how they function (as your explanation is so good!) (summary, 1st/lowest valve throttled siphon; 2nd/middle-height has an air tube connected near max peak that breaks siphon so it runs "open" but will revert to siphon if the air intake becomes submerged by rising water level; 3rd/highest open drain for failsafe). I'll try to explain what I'm curious about, which is only the 1st/lowest drain, the one we want to run always in siphon handling ~99.9% of the flow. The 2nd and 3rd drain must be implemented one of the ways you've described in order to function as cascading failsafes.
Regarding the 1st/lowest siphon drain.
I'm thinking that the 180 PVC tube/fittings on top are redundant when we're draining an external overflow box straight down to the sump. There is no "hump" the siphon has to travel over. Essentially, construct it like the 3rd "open" fail-safe drain, an open pipe but of height well below the 2nd open/siphon drain (with possible strainer for debris) but the the rest as described: throttled by the flow tuning valve with the bottom submerged 1" in the sump. On startup, the water level in the overflow box will rise and the top of the tube will be entirely submerged. Throttled by the flow-tuning valve, the water level will rise in that tube and any air within that tube will be flushed out to the sump. Now we have a submerged intake and submerged outtake, and a tube filled entirely with water without air and the weight of the water in that tube pulling the water out of the overflow box: a siphon - with the orientation of the intake irrelevant as long as it remains submerged (with the bottom submerged as described to facilitate startup). As the valve was tuned to limit flow to ~99.9%, the water level in the overflow box (as determined by the 2nd drain height running in open mode) will remain above the opening of the primary drain tube, such that only water, no air, will be sucked into the primary drain, maintaining siphon.
Playing with a rain barrel suggests this is the case.
wouldn't this work in an external overflow box: yes? no?
BeanAnimal
Premium Member
Ahh... you were referring to the down turned elbow in the siphon standpipe!
Yes, depending on the configuration of the external overflow box, it can be run open top. There may even be some photos here in the thread of setups with open top standpipes.
The biggest problem is that they can easily create a vortex that will pull air in from the surface, even if they are submerged several inches. This also depends on the geometry of the box, the size of the pipe and the flow through it.
An open top standpipe is also much more susceptible to clogging than the down turned elbow. As you mention, a strainer can help, but again this will depend on the size of the plumbing and overflow box.
If you have the room and take the proper precautions, then you can certainly run the siphon standpipe open topped.
That said, at any reasonable flow with any reasonable drop, there is no problem getting the siphon started on the weir type standpipe with the down turned elbow. On a system with very low flow, drilling a few small holes above the normal operating water line in the sump will help to ensure that the air is easily purged.
Ahh, the vortex...
Well, it seemed like a good idea.
I immediately started thinking of fin arrangements to prevent vortex, but we already know the down-turned elbow works.
thanks
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