what is a siphon break?

[The Reefer91]

i'm wondering what a siphon break is and where you would locate it.

 

[gobygoby]

Location: usually in an overflow U-tube.


What is it: when the water that is siphoned from the tank to the overflow stops = "siphon break"

 

[The Reefer91]

1. what exactly is a U-tube

2 i didn't know that you used the power of siphoning in a internal overflow. thought it just was powered by the pump

 

[gobygoby]

as you can the the tube in the over flow is shaped luke a U...hence "u-tube". this is wahere the "siphon break" occurs. it usually happens because air bubbles get trapped in there or a power outage

this draws the water out of the tank and drains it down to a sump below. then it would be pumped back up to the tank.

This does not realate to a "hob" hong on back filter as you are refering to.

hth
Goby

 

[The Reefer91]

oh, i'm not using that kind of overflow. i'm using the ones that are like black boxes inside your tank, and have holes drilled in the glass. but i'm curious, does a siphon break have anything to do with "internal" overflows?

 

[gobygoby]

<a href=showthread.php?s=&postid=6582188#post6582188 target=_blank>Originally posted</a> by The Reefer91
oh, i'm not using that kind of overflow. i'm using the ones that are like black boxes inside your tank, and have holes drilled in the glass. but i'm curious, does a siphon break have anything to do with "internal" overflows?

no, an internal overflow does not use the power of siphon. its gravity

 

[The Reefer91]

ok. so i don't need to even think about siphon breaks

 

[gobygoby]

<a href=showthread.php?s=&postid=6582270#post6582270 target=_blank>Originally posted</a> by The Reefer91
ok. so i don't need to even think about siphon breaks

no

 

[theop]

I think the siphon break you are asking about has to do with your return line.

You need some small holes in your return line slightly below the water line. This will prevent a back-siphon of water going from your tank to the sump when you turn off the sump return pump (or if it fails). Without these, your tank water level will drain down to the level of your outflow nozzle.

 

[The Reefer91]

yeah, that's what i was thinking of. ok. thanks so lsightly below the water line?

 

[theop]

You want them far enough below the water line to not have the flow coming out of the holes causing surface bubbles and salt creep. But you want them high enough that when the tank drains down to the level of the holes it can be contained in your sump without flooding.

I have mine about 3/8" below the water line. My holes are about 3/16" or 1/8" in diameter. Holes that are too small will clog easily. You also want at least 2 holes to reduce the risk of blockage by algae or a snail. I have 4 holes - one at every 90 degrees.