is there a trick to matching return flow on a herbie?

[04scoobysti]

The only problem i could see (looks like you have a gate valve) is that your herbie is located in 2 different overflow boxes. That might make it more difficult to tune. Also the wavebox is running in the same direction as the overflows, this would make more noise if the wave trough drops below the overflow teeth. Almost a surge of water when the wave crests back at the overflow.
My 2cents.

[Dez]

I have a wavebox and overflow on the same side like yours. I have no standpipe on the main drain and a full length standpipe on the emergency drain. It wasn't bad to adjust. Slowly close the gate and wait about 10 minutes to make sure everything is equalized. I have my water level in the overflow box slightly below the emergency standpipe. With the surging and changing water levels, my system is still quiet. The wave box is probably the noisiest part of the system and thats the hum of the constant on/off of the wavebox pump. Hope this helps.

[Milad]

well i was trying to tune it with the wave box on which proved bad

i do have a gate valve, two seperate overflow boxes. no stand pipes in them. basically the overflow boxes are the stand pipes.

what do the holes do in the stand pipe?

[Dez]

If you are planning on running your wavebox, then I would tune it with the wavebox. That's what I did and no problems. If you tune it without the wavebox on, then once you turn the wavebox on the surging water could potentially surge in and out of the emergency standpipe (which is what happens if I run my overflow box water level too high, then it gets loud). Hope this helps.

[viperfish]

Two standpipes in mine, emergency overflow is 3" higher than the main. I have the water level adjusted just below the emergency overflow and runs whisper quiet.

[trilinearmipmap]

OK here is the reason for a perforated standpipe and how you can make it work with the wavebox.

If there were no wavebox then tuning the Herby would be easy, just slowly adjust the gate valve until the water level in the overflow is just right to give no sound.

Now the perforated standpipe is to give you a margin of error where the Herby will function properly whether the water level is a little higher in the tank (top of the wave at the overflow box) or a little lower in the tank (bottom of the wave at the overflow box).

You want the bottom of your standpipe to be full at all times, to have enough water pressure to to this the water level within the overflow box will have to be x number of inches above the lowest perforations. The exact amount of inches will depend on the amount of flow through the overflow, the diameter of your standpipe and drain pipe, and the surface area of your perforations. But lets say 6" above the bottom perforations in the standpipe.

You also don't want the water level in the overflow to be too high or it will start to come down the emergency drain and make noise too.

By having a large height of perforated standpipe, you can set the water level in the the overflow box to about the middle of the perforated area. When the wave is at its lowest, less water flows into the overflow box, the water level in the overflow drops a bit, but it is still high enough to provide enough pressure to completely fill the bottom of the standpipe. When the wave is at its highest, the water level in the overflow goes a little higher but still not high enough to go down the emergency drain.

You can do this with no standpipe at all, however there are two drawbacks. Anything large getting into your overflow can hang up at the gate valve and partly block your flow. And the drop from the overflow weir down to water level in the overflow will be high enough that it will make some splashing noise.

In addition using a standpipe allows for a permanent area of protected water to form in the overflow box ie. a non-lighted refugium which can be a benefit for diversity.