Herbie Overflow Siphon Start/Restart

While I'm waiting on my pump to arrive I've been giving some thought to the process of filling the DT and getting the initial siphon started. I have an internal overflow box with one downturn elbow (main) and one upturn elbow (emergency). I can easily see how when I fill the DT the water will flow through the main drain into the empty sump. But I can't quite see how the siphon will restart after a power outage if the sump is full of water, the drain pipe is empty and sitting below the water level in the sump. How will the air in the pipe be purged to allow the siphon to start?

By the way, drains are 1" and the return is 3/4" with Mag7 pump.

Thanks!!

 

Yeah... I could never figure that one out either.

 

I thought the Herbie overflow does not use a 'siphon', but rather works like a drilled tank so that when the power is on, it overflows to the sump.

??
Never studied it fully, I don't have one

However, if it's not drilled somehow/way, you'll need a 'siphon' to get the water up over the tank edge, that's what they're for, the siphon that is

 

On your main drain (siphon) do you have a gate valve on it? I run a herbie overflow on my 300 FOWLR for almost 10 years now. Once you have the gate valve dialed in, it will always restart after turning your main pump on and off. When I do a water change, it takes a couple of minutes and the siphon restarts. I'm not sure about downturn elbow. I haven't read up on herbie overflows in 10 years so I don't know if there are changes to it ;D But on my setup, the 2 drains are in the same overflow box. Both have straight pieces of PVC tubing with no elbows. The main drain/siphon pvc tube is cut shorter than the emergency drain.

 

hmmm...

I may be wrong but, I believe it will become a siphon with a downturned elbow as long as the water has room in the overflow to initially rise up above the elbow by 1-2 inches.

The water level will quickly drop once the air gets purged and the siphon begins.
The siphon should start due to the change in pressue with in the drain.

At the same time when the water is rising in the overflow before the siphon action begins, the emergency standpipe will accommodate the extra water if it rises too high.

Once the siphon has been running for a bit, your water level will resume back to normal.

 

The siphon line will purge the air out the bottom into the sump over the first couple of minutes after you start up the system.

 

^ what they said.... sometimes it takes awhile for it to balance itself out (water level in overflow will rise and fall for a few minutes until all the air is out of the drain pipe) but once it does it's good to go.

 

There is no siphon on the Herbie...it's just a stand pipe that is flooded with no air. The emergency is just a stand pipe. An up or down turned elbow is completely unneeded.

Nothing has to "start". The pump starts, overflows the tank, overflows the drain, and that is it.

Now there will be air in the line. as long as there is air, it can't fully flow water, and flow is reduced. So then yes, the air will get purged out, and after that, everything is good.

 

There is no siphon on the Herbie...it's just a stand pipe that is flooded with no air.
What?
...that makes no sense. If it has no air, it's vertical, and full of water, it will turn full siphon if the water level can keep up from the return.

The emergency is just a stand pipe. An up or down turned elbow is completely unneeded
The emergency does not need an elbow that turned up or down.


The entire point of the downturned elbow is to keep the setup quiet.

Not sure where your going with this argument unless you're just looking to say that adding a 90 degree elbow to a standpipe isn't a herbie...

I stand by what I said earlier...