General Theory
There are two threads with similar designs the one by
Herbie and the one by
BeanAnimal this will hopefully explain the difference between the two and how they work at least as I understand it. Let me start with something Hookup said:
Originally posted by Hookup (9/14/09)
Noise reduction... Period. If you do not care about noise, then put in a single 4" diamater pipe, or a bunch of 1" pipes, etc... it's easy to get water to your sump if you do not care about noise.
The quitest possible solution will be a pipe with no air and all water... a 100% flooded pipe. The second quitest pipe in the world will be a pipe with very little water and lots of air... the water sticks to the outside of the pipe, the air is in the middle... so long as the flow of water is low enough, this system stays put and it's pretty darn quite. As the flow increases, the friction between the water and the air causes "waves" and creates crashign noises... so the flow needs to be low...
If you can use either of those "noiseless" situations, you've achieved success, from a managing noise perspective.
The challange is simply that the amount of water returning to your system is unknown and difficult to pin-point. It also might change slightly throughout the life of the tank.
This challange, makes creating a single "flooded" pipe next to impossible. It therefore leaves us with a two options... Just use the low-flow trickle system that is virtually silent, or use a combination of both... Herbie, posted first, that using a combination could work most effecitvely. Bean just cleaned it up and made that info a bit more digestable.
Both Bean & Herbie systems simpy combine those two noise-reduction methods to create a managed tank-to-sump water flowing system.
One pipe is running full of water, call that a flooded pipe. This pipe is "tuned" via a gate valve, where in you are trying to closely match the volume of water coming back to your tank via the return pump but not trying to go over.. so it must run at .... (return pump volume)gph - (some small percentage)... but also must remaine 100% flooded for a noiseless state to be acchieved.
The second pipe is running at a very low flow rate. This pipe is not tuned, but simply catches any "extra" water that the other pipe could not handle... Over time, if things shift, this pipe will switch between low-flow with air, and no-air... which will create a very loud gurgle noise... letting you know something's up.
The fact that this might be in a box or in a pre-drilled tank, or anything like that seems irrelevant. The fact that one design has a bend in the pipe and the other doesn't is again, not really relevant.
The concept is identical, one fully flooded drain-line and one low-flow drain line tuned to match your return line volume. (Bean added a 3rd pipe for extra-extra saftey is all)
The thing to realize, is that all of the PIPES in my above laymans description are simply between the tank and the sump... how you get your FLOODED PIPE FLOODED and your LOW FLOW PIPE with LOW FLOW is up to you. Coast-to-COast, interal boxes, or free-standing center fo tank drilled pipes all can work... and all have different surface skimming advantages and disadvantages... but these designs are about noise...
Simple right?
The only thing I might disagree with is that BeanAnimal added the low flow drain, but since some people do that with the Herbie method I can also see Hookup's way of thinking.
If you want set and forget follow the direction outlined pretty well on the first page of each thread (and I have tried to summarize here). If you like to tinker by all means experiment (but I would read both threads). This is general idea and summary 9at least the best I could do). Also the two thread use some what different terminology, so if you have been following along the words are little different, but you probably won't have a problem. If you haven't been following along then do you really care what a summary calls them
.
The main theory behind this is a drain that does not allow any air in. As long as the drain does not create a vortex and suck air it is silent. The next step is that the output must be under water otherwise you will hear splashing as it returns to the sump. The valve is installed to regulate the water flow so that the water level is high enough to prevent a vortex which is the noise in most cases we are trying to avoid. This is all that is required for silent drain, but there are two main problems:
possible blockage (pesky snails
or is that algae).
regulation (so it is kept silent)
The difference in the two design is how thay went about fixing them.
So the idea of an emergency drain came in. The emergency drain is set higher than the regular drain, and if the main drain becomes blocked takes a partial or full amount of the water. It should drain above the water so that splashing is heard if it is actived (to alert you there is a problem "“ you want the emergency drain noisy). The Herbie method then balances the water height between the two drains with the gate valve. Regulation is then (generally) handled by more or less water in the overflow. More water means more pressure and a faster flow through the drain. Less water, less pressure and a slower flow through the drain.
Balancing can be very hard especially if the height difference was very small such as a Calfo system "“ this is why Herbie's design did not work for BeanAnimal. BeanANimal realized that if the water level is adjusted so that a small amount of water went in the emergency drain it was much more stable. But if the emergency drain is being used is it really an emergency drain? So a third drain was added to the BeanAnimal design.
Both designs are for a quite tank with fail safe. The difference is in regulation. The Herbie method was designed for a reef ready tank and relies on a tall overflow box for regulation and can be done with two overflows. The BeanAnimal uses an additional output for regulation and was designed for tanks that can have three holes for draining (originally designed for a Calfo style tank, but would work on any tank that has three drain holes).
From now on they will be referred to as the main drain "“ water only (in threads sometimes referred to main, normal, siphon), open drain (air and water) and emergency drain. It is a personal call how much redundancy you want some people are talking four drains. As I mentioned for silent you only need one for failsafe you need more (highly recommended).
WARNING
This may not work with HOB that are siphon driven from the main tank. If a drain fails the water level start to rise to the next drain. Now there is less flow from the tank since the tank/HOB water differential is less. So the tank may fill up faster than the siphon can fill the HOB.
Main Drain
This can be a straight pipe. The only requirement is that it can not suck air. BeanAnimal shows an elbow, because of his relatively low water height he needed the elbow to help prevent a vortex from forming. There are many ways to prevent a vortex this is just one. This should drain into the sump just below water level; too far and it will be hard to start the water flow due to back pressure. If there is a choice this should be the smallest of the existing bulkheads (at least the way BeanAnimal suggests things). The system Herbie designed actually used the smaller tube for emergency, but in my opinion if the small drain can't take the full flow then it shouldn't be the emergency. In a BeanAnimal design this drain should be lower than the open drain so there is enough water to fill and flush the water from the main drain before the open drain takes water in.
Open Drain
This is not used in the Herbie design. This is often made into a Durso type standpipe to keep it silent in the BeanAnimal design, although if the water flow is low enough it is not needed. It should have a minimal amount of water flow. For a BeanAnimal design this should be the larger than the main drain if a choice is given. A larger pipe will we quitter when air and water mix.
Emergency Drain
This should be higher than the other standpipe(s)/opening(s), but low enough that the water can cover without a vortex forming so that maximum water flow can be obtained.
Start Up
As the water fills the overflow it will drain down the main drain. If the pipe can not handle the water flow with the valve all the way open you have a problem. Now back the valve off until the water level is just going down the open drain (BeanAnimal) or between the two drains (Herbie). Some people have reported problems getting the main drain to flow the full amount of water (no air) in the BeanAnimal design. BeanAnimal suggests a small whole just below sump water level (less back pressure). It can also help to have the intake lower than the open drain so that it gets more pressure to start the flow.
Stand Pipe
This is for those with an over flow box in tank. Do you need one? NO. The reason for a stand pipe is to keep to much water returning to the sump in the event of a power failure. Most people have one.
Screens
Required? NO. They are highly recommended to keep items from getting into the drains (even the emergency drain).
Emergency Drain
Required? No. It will work without. You may just be asking for trouble (flood). If you don't have then you don't have a Herbie of BeanAnimal.
Gate Valve
A gate valve seems to be easier to adjust, but it was mentioned that they are likely to leak (read the post for more information). An overflow box should be easier to adjust since you can have more height between your drain pipes when using the Herbie design.
If the both ends are underwater (as designed) I don't think it matters where the valve is. However, I think BeanAnimal once said to place the gate low to get all the air out so you don't hear the water trickling down the pipe after the valve. I believe he placed his high for convenience and lack of space in the sump. Another BeanAnimal comment on this:
Originally posted by BeanAnimal (8/22/09)
If the sump is in the basement, the siphon adjustment valve should be there as well (to prevent cavitation on the LONG drop).
Two Drains "“ Over Flows
This is pure theory, but may explain why some people are having problems if they have dual overflows.
I do not think that two drains can have different flow rates unless one is to the top of the overflow. Assuming a level tank half the water will go into each overflow. So if they do not both drain half the water then one should eventually fill up. I said it was theory. Also two drains are hard to adjust (so I have read), so I think the best advice is to tie (tee into a larger pipe) them together before the gate valve.
I can't say for sure on this, can any speak up on this. It was a common question and I think every ended up tying them together. I am just trying to cover all the questions.
Teeing Drain to 2 Locations
This can be very hard to adjust. People have done it by gating one of the tees. If you want simple no questions asked operation don't do it. If you want to fiddle give it try and send me your results to I can update this section.
Also I think both drains should be in the water for silence so both levels will need to be the same (or a siphon will form and make them the same from what I have read).
I think I have read two different ways to do this. One with a valve before the tee and then another valve into the fuge. The other had a valve on each leg after the tee (one for fuge, and one for skimmer section).
Tying Open and Closed Drain Together
Generally this is expected to cause noise. I don't think I read of anyone getting this to work (if I am wrong please update me). BeanAnimal's theory was that the open drain would allow air to be sucked into the full flow make noise.
Guide lines
- Use the smaller pipe for the main drain (BeanAnimal)
- Drain into a bucket (fixed water level) to keep the output level constant (this makes tuning easier).
- Emergency drain is above the water; you get splash warning that something is wrong.
- Two drains should be tied before the gating valve
- Teeing the drain to a sump a fuge is not recommended (unless you like to fiddle)
- Water level above pump should be constant. These means less fluctuation in the water level over the main drain.
Common Questions
Over Flows
These systems can work any tank (except maybe HOB see above) with the proper number of bulkheads. So yes either system can work with a Calfo or in tank overflow.
Sanitary Tees
These are not required, but will help with the flow since there will be less resistance. They are not found with pressure fittings but with sewer, drain and run off piping. They are hard (impossible ?) to find in 1 inch.
Pipe Order
The pipe order does not matter.
PVC Caps/Cleanout
These are shown in BeanAnimal's design. These are there for two purposes. The first is so that the drains can be cleaned. The second is to help start the flow. Air can be compressed easier than water.
Originally posted by BeanAnimal (8/22/09)
The Tee is not really even needed on the siphon or emergency standpipes, an elbow could be used instead. For that matter, you could use an elbow for the open channel as well (you would tap the top of it for the air line). The Tees just make things easy to work with and allow the addition of a cleanout. You would be amazed at how much organic material can accumulate over several years. Fan worms, macro fauna, slime, etc.
Putting the top of the cleanout at or above the rear edge of the tank simply facilitates maintenance and will prevent the overflow of the system in the event that you have a leaking cap or wish to do service while the system, is running..
Plumbing
I think the plumbing should be as strait as possible. When I redid the plumbing too pump over the top my water flow increased (maybe doubled looking at the water going into the overflow). I took a 4 foot vinyl tube and cut in to 2 feet straight run and significantly increased my drain flow.
Water Flow
A lot of people are asking how much they can flow with a drain size of X. Somebody posted this link (sorry I don't remember who).
Water Flow
DISCLAIMER:
This is what I understand after reading both threads. It does not mean that I got it all right. I also apologize if I put words in BeanAnimal's or herbie's mouth, obviously I don't think I did.
The more complicated the plumbing-- the easier it is to stop up the drain! Thank you Scottie! You can read the first page and know all you need to know to implement this drain system.
