Return line siphon break?

[rob020880]

Can anyone tell me who to create a siphon break on my return line. I worry that I will flood if my return pump loses power. I saw somewhere a part that you can attach to the return line that will eliminate this problem. Is anyone familiar with any of this?

 

[areze]

I assume your talking about a check valve, its a common choice, but should not be used(or at very least, not relied on)

the simplest way to protect yourself is to drill a hole in your return line right at or just under the water line in your tank. that way, as soon as this small hole is exposed, it will suck air and break the syphon. I suggest drilling atleast 2 incase a snail or something decides to block 1. reduncancy is always your friend.

 

[jtarmitage]

Great answer areze, my thoughts exactly. The problem with the check valves is that they WILL clog over time, so unless you make a habit of taking them apart every couple of months, they may not completely seal when the flow stops, and you end up flooding your sump. I used to have them on my system, and found out just how much of a problem this is when I shut down my return pump to do some in tank maintainance. Just glad I was there to notice the splashing sound as my sump was starting to overflow. Drill syphon breaks and check them now and again as you are cleaning the tank.

 

[AZDesertRat]

As long as the returns are close to the surface it will only siphon a slight amount of water back to the sump until the returns are exposed. This is the safest way to design a return. Drilled siphon break holes plug with algae, snails, food, etc. Check valves fail with a single grain of sand, small snails, food, wear etc.
Maintain enough room in the sump for a worst case backflow and keep the returns close to the surface and you can sleep at night. My 100G backsiphons a worst case 4.5 gallons back to my 30G sump so I keep about 8 gallons of room available at all times so I have a safety factor. It has never come close to failing in over 3.5 years.

 

[areze]

while I agree full heartedly with you, and do what you have said, I would put holes in addition. some things in the sump for me are sensitive to levels. specificly my skimmer, so while there is plenty of room for the slight backflow if my holes were blocked. its better if it doesnt.

redundancy is best.

I dont care for a check valve for a level of redundancy because it has some resistance to it as well.

 

[rob020880]

But if I drill the return line won't water spray out of there? How big should to hole be, and should I drill it just below the water level of the tank, or the waterlevel of the overflow?

 

[areze]

IME the water doesnt spray out, there shouldnt be that much pressure. I have holes drilled in mine (locline) just over the water line, it has not failed to stop the syphon before it ever starts.

but it COULD clog with salt, so I have a hole under the water line as well.

the hole over the water barely trickles if at all. water prefers to just follow the easy route down the tube. unless you have the end in a jet nozzle or something.

 

[Worldwithin]

You don't need to drill a big hole at all to create the break. I think I drilled a 1/8 hole on my two outputs, just below the water line, angled down. Water does exit the holes when in operation, but since I angled them down, you don't see it at all. When the pump / power turns off, they break the siphion almost immediately, draining maybe 1-2 gallons into my sump.

:fish1::hammer: