Silent and Failsafe Overflow System

[thejuggernaut]

So all of the warnings about the 2 line system should be ignored? I know I will only be putting 600gph through the overflow but I am still nervous.

Ran one for years before I eventually turned up the flow a little and installed the third back bulkhead like I described above, but I never had snails, I hate those little ugly things crawling all over my glass. Plus most people don't run a true Herbie. They incorrectly use the dry emergency as the open channel and it always handles a little flow. The whole point is to get the drain completely out of the water column so nothing will climb up in it or get sucked down it to clog it. The Herbie does require more tuning, both initially and in the future as algae coats the pipes and you get small changes in flow. I believe most floods are due to neglect, and if you take 3 seconds to inspect your system daily, then you can probably avoid most issues and your risk is manageable.

 

[uncleof6]

So all of the warnings about the 2 line system should be ignored? I know I will only be putting 600gph through the overflow but I am still nervous.

As juggernaut was saying, the warnings about the 2 pipe siphon system, or "Herbie," concern the use of a wet secondary, or a "trickle of flow" in the dry emergency. The idea behind the use of a wet secondary with the "Herbie" is to take care of the inherent instability of the system, caused by moderate variations in flow rate. The "Herbie" is not supposed to have a wet secondary, and the wet secondary was not used till after the publishing of Bean's design.

The "Herbie" will self adjust, without the use of a wet secondary, due to changes in pressure head (water level,) but the band width is rather narrow, limiting self adjustment to "small" variations. Under normal circumstances, it should not require constant re-adjustments, rather "periodic" adjustment, the interval of which will vary from system to system. So what should not be ignored is the safety risk involved with running a wet secondary, as the "inherent instability" is not great enough to justify the flood risk.

I have seen only one instance where the variation was causing a problem (near flood or near famine) but the problem was the pump output varying, for reasons we never did figure out for sure. I suspect that constant need to fiddle with the adjustment, would be due to not getting it set in the "sweet spot" balancing the drain capacity with the pump output. For that reason I recommend gate valves over ball valves to get a finer adjustment.

 

[uncleof6]

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[uncleof6]

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[adova]

I have been noticing that the water height in the overflow box changes over time without any adjustment to the valves. The variable that does change (as I am still setting up) is the sump level where the return pump is located.

Can the sump level affect the pump output and hence the overflow water height?

 

[Reefer PT]

Thanks for the clarification. I think I will be fine as long as I remember to look at what the overflow is doing everyday and make sure the dry line is staying dry. I have already purchased the gate valves so this should not be a problem. But I am still tempted to change things up and go c2c. Seems like a shame after spending so much on the overflow already though.
Dave

 

[uncleof6]

I have been noticing that the water height in the overflow box changes over time without any adjustment to the valves. The variable that does change (as I am still setting up) is the sump level where the return pump is located.

Can the sump level affect the pump output and hence the overflow water height?

Yes it can. The variable is called the Net Suction Head Pressure Available. This defines the water height or pressure head above the pump inlet. Depending on the water level, the static lift the pump needs to overcome either increases or decreases, with decreasing or increasing water level, respectively. This of course will cause a small variation in pump output.

 

[uncleof6]

Thanks for the clarification. I think I will be fine as long as I remember to look at what the overflow is doing everyday and make sure the dry line is staying dry. I have already purchased the gate valves so this should not be a problem. But I am still tempted to change things up and go c2c. Seems like a shame after spending so much on the overflow already though.
Dave

My advisory for going with a "Herbie" rather than a Bean, is predicated on not having to do major modifications to the tank itself. By far the ideal setup would be to remove the current overflow(s), plug existing holes with capped bulkheads, install a C2C overflow, drill three holes out the top/back of the tank, and go BA. The effort is worthwhile, but not many are willing to put forth the effort. I encourage folks to buy "blank slate" tanks, rather than "reef ready" tanks. That way, you don't have the added chore of undoing the "limits" placed by the manufacturer.

 

[woodnaquanut]

+1. Pic please

I'd take a pic but it's black acrylic, black gutter guard and a dark narrow space.

Think black cat, moonless night.

I'll try to take a pic but no promises it will be worth the electrons used to take it. :dance:

 

[woodnaquanut]

OK some pics.

Below the waterline



Above the waterline


Looks like it's time to take a toothbrush to the gutter guard! :eek2:

 

[rickztahone]

cool pic. How did you install it? Silicone?

 

[thejuggernaut]

While flow testing my new overflow today I decided to make a video. I ran it at three different flows. 3000, 2000, and 700. They system would handle more flow but would probably start making noise and introducing more bubbles. I also simulated clogging both the siphon and open channel at the same time to make sure they system was as leak proof as I could make it.

https://www.youtube.com/watch?v=oya6X3aLUOo&feature=youtu.be

 

[Floyd R Turbo]

Great video! The only thing I would recommend is lowering the OC so that the opening on the top of the pipe is below the level of the emergency. You really want this to engage before the water gets over the emergency. Also you might put the cap back on, leave the gasket off, and drill a few holes in it so that it allows air to intrude.

Looks like the placement of the pass-through bulkheads works pretty good, I thought you would get more bubbles than you were at the 2000 and 700 GPH levels (which is what I have seen).

Very good to see this in action - the emergency kicks in and handles the full 3000 GPH very quickly, with what appears to be only 1" of water over it.

Great demo! Thanks for posting!

 

[shaggss]

Hi Uncle

Is this the right stuff?



If so should it look like this or is this a bad bunch?

 

[thejuggernaut]

Turbo,
I adjusted the OC up on the higher flow rate in order to submerge the bulkhead. With the water below it, it made more bubbles. I plan on running it at around 1500-2000 GPH which I feel was a good sweet spot and was completely silent. Around there I can run the pipe lower. Yea, the pipe being completely open does make a gurgling noise, so I will probably do as you instructed. I may use the airline trick everyone uses. That would allow me to set my water running height and the height that the siphon kicks in independent of each other. I also plan on making a lid to fit over the whole box. As far as the no bubbles, I think the secret is the overflow box. At 2000 GPH, the water flows over so nicely that it sticks to the wall of the box and doesn't make any gurgling or bubbles.

 

[thejuggernaut]

Hi Uncle

Is this the right stuff?



If so should it look like this or is this a bad bunch?

I've used something similar on iron pipe for gas lines, and on copper lines for my air compressor lines running through my garage. Mine was yellow, but it looked lumpy like that also. Still hasn't leaked in three years. On the canister it said it was good for PVC as well.

 

[Floyd R Turbo]

You can also put a 90 degree JG fitting on the OC plug, then take a piece of tubing that has a slight bend to it and push that in there, so that the tubing is pointing down, and then the tubing will control the point at which the OC converts to siphon.

 

[woodnaquanut]

cool pic. How did you install it? Silicone?

No - it is removable! There is a little channel inside the OF box that the gutter guard slips into.

 

[rickztahone]

No - it is removable! There is a little channel inside the OF box that the gutter guard slips into.

great idea. I will try to emmulate this as well.

 

[rickztahone]

Great video! The only thing I would recommend is lowering the OC so that the opening on the top of the pipe is below the level of the emergency. You really want this to engage before the water gets over the emergency. Also you might put the cap back on, leave the gasket off, and drill a few holes in it so that it allows air to intrude.

Looks like the placement of the pass-through bulkheads works pretty good, I thought you would get more bubbles than you were at the 2000 and 700 GPH levels (which is what I have seen).

Very good to see this in action - the emergency kicks in and handles the full 3000 GPH very quickly, with what appears to be only 1" of water over it.

Great demo! Thanks for posting!

Read what I made bold. I was under the impression that the air line, or in this case, the top part of the p-trap was supposed to be above the emergency. At least that has been my understanding.