Herbie overflow help

[19jonesy86]

As the title stated I have a herbie overflow on my 200g setup, I've been thinking long and hard about what on earth happens if there is a power outage, will my sump overflow? Do I need to bring the main drain pipe up higher so my sump can handle the excess water from the DT in the event of an outage!? Someone help please?

 

[johnzena]

As the title stated I have a herbie overflow on my 200g setup, I've been thinking long and hard about what on earth happens if there is a power outage, will my sump overflow? Do I need to bring the main drain pipe up higher so my sump can handle the excess water from the DT in the event of an outage!? Someone help please?

Part of your design should be that your sump handles the water drained from your tank in the event of a power outage. My tank empties one inch when power is lost.

 

[19jonesy86]

Part of your design should be that your sump handles the water drained from your tank in the event of a power outage. My tank empties one inch when power is lost.

Yeah for some crazy reason I was thinking my tank will drain into my sump hahaha but it's in fact just the water in the weir down to main drain is that correct?

 

[johnzena]

I dont know your set up but to explain my set should answer your. I have two overflow boxes in my tank. As water enters the overflows they fill up to the point that the water flows thru the herbie and down to the sump. In a power outage water will drain through the herbie until the water in my tank no longer enters my overflow. It is only about a half inch. Several gallons at most.

 

[johnzena]

As a side note you must have a check valve on yuor return. Without one water will siphon backwars thru your return pipe and the tank will empty to that point. I have one return about 6 inches below top water level.

 

[19jonesy86]

I'll try explain my set up best I Can, I have 1 overflow with 2 drains (main and emergency) the emergency will sit just below water level in weir and the main is about 5-6" below that. Will drilling a hole just below the water line on the return do the same as a check valve?

 

[jaws789832]

Turn your return pump off and see what happens. Be ready to turn pump water out of the sump and turn you pump back on just in case. The only water that should go into the sump is everything above the weir. As stated above water can backflow from the return, so set your returns so they are just above the weir height. Pictures would make it easier to tell you if everything is OK

 

[jaws789832]

Is the tank bottom drilled?

 

[jaws789832]

So what should happen in that case, and this is as long as your overflow is sealed up good(no water gets into the overflow from the side, only over the weir). When the return goes off the tank will drain down to the bottom of the weir, then the overflow will drain down to the main drain. Your sump should be designed to handle that much water with a little room to spare

 

[19jonesy86]

Turn your return pump off and see what happens. Be ready to turn pump water out of the sump and turn you pump back on just in case. The only water that should go into the sump is everything above the weir. As stated above water can backflow from the return, so set your returns so they are just above the weir height. Pictures would make it easier to tell you if everything is OK

One return will be just below the water line the other is about water hight.

I have a valve on the main drain as you can see above. Hope the pics help.

Is the tank bottom drilled?

Yeah it's bottom drilled.

 

[jaws789832]

A hole will break the syphon on the return line but they are apt to get clogged over time. I just keep the returns at about the same height as the weir so you don't have to worry about it. A backflow preventor will work too but they too over time can fail and still let water syphon. I try to design the systems so there is no possible chance anything can overflow.

 

[19jonesy86]

Ok thanks my mind is at ease now. As you can see from the pictures the tide mark on the sump is where I'm assuming the water will get to at normal flow rate, it's a 60g sump so should be able to handle the 6 inches of water from the weir. I'll change the left return inlet to match the right one so they are both around water height that way will minimise back siphon.

 

[jaws789832]

First thing I would do is put some water in the overflow to make sure it doesn't leak back into the tank. If it does reseal the overflow. I would take off the downward facing elbow on the left side return line and make it match the right side. purchase some LOC line return hoses and jets https://www.bulkreefsupply.com/loc-line-modular-hose-segments.html that way you can adjust the return line heights and flow direction.