Help with herbie emergency drain

[FluffySackson]

Using an herbie overflow on this tank, shut off the main true union ball valve to test the emergency drain, but it seems the display's water level is rising to the brim. My pump has a gph of about 630 yet my main drain isn't flooded by it either, in fact I need to turn the valve about 1/5 in order to gain a full siphon. What's going on?

 

[bbortko]

Does the emergency drain have full siphon? It may be to tall in relation to the overflow. If debris builds up over time in the main drain you're going to have to keep fiddling with the valve so you're going to have a warning that the main needs cleaning, what size are the drains and what in the tank could cause 100% blockage?

 

[DN328]

Based on my experience, it's expected that the full siphon drain needs to be reduced via valve to create a full siphon and not make tons of noise- perfectly normal.

If you've closed the primary drain to test, the water would rise to/above the level of the second drain. It will continue to do so as the second drain now needs to take on the full flow of what the primary drain had taken on (although there may have been a slight trickle to your second pipe). I assume your drain pipes are both the same size? Also, what is the height of the second drain relative to your overflow? The water will rise, so you'll want to make sure the second drain can take on the full load before the water overflows the tank.

It's a good test that you're doing, but keep in mind that the primary drain won't always be fully blocked either. But good that you are testing this way.

I think answer the questions will help to troubleshoot your situation.

 

[ragin_cajun]

What size pipe are your drains? Emergency and main/siphon drains?

The gate valve on your main/siphon drain will probably be almost completely closed to achieve full siphon. That's not unusual. Mine stays closed almost entirely.

 

[davenmandy]

Sounds like the emergency might not be big enough?

 

[FluffySackson]

The emergency drain is a 1" bulkhead and pvc, same with the main siphon.

 

[jandb]

Based on my experience, it's expected that the full siphon drain needs to be reduced via valve to create a full siphon and not make tons of noise- perfectly normal.

If you've closed the primary drain to test, the water would rise to/above the level of the second drain. It will continue to do so as the second drain now needs to take on the full flow of what the primary drain had taken on (although there may have been a slight trickle to your second pipe). I assume your drain pipes are both the same size? Also, what is the height of the second drain relative to your overflow? The water will rise, so you'll want to make sure the second drain can take on the full load before the water overflows the tank.

It's a good test that you're doing, but keep in mind that the primary drain won't always be fully blocked either. But good that you are testing this way.

I think answer the questions will help to troubleshoot your situation.

I think that will help you. The secondary has to be low enough to create a full siphon before it overflows. Hopefully it'll never happen but can't be too prepared. Head over to reef central and check out the original thread by herbie. It's hundreds of pages worth of answers and different scenarios.

 

[ragin_cajun]

The emergency drain is gonna drain A LOT slower than the main/siphon drain until it catches full siphon--if it ever does.

Ideally, the emergency drain is big enough to drain the pump output without catching full siphon. That's real noisy, but ya don't care about noise anymore at that point.

And if you have to cut your emergency drain too short, you'll get noise from water falling down the back of the weir.

 

[ragin_cajun]

This probably gonna cause a long thread with lots of debate....but, I'm gonna say it.....come what may.


A 1 inch pipe in this scenario drains 600 GPH. Your E Drain isn't big enough. Drill some drains or get a smaller pump?

http://www.reef2reef.com/threads/1-pvc-flow-rate.125543/

 

[FluffySackson]

the overflow