How to hopefully prevent your tank from over flowing (video)

Sgt Jonny Cat · 04/30/2015, 12:54 PM

Hi guys, I just wanted to share this one with you all. It's a video that discusses siphon breaks in your return line... Enjoy!!

https://www.youtube.com/watch?v=s10VX0dYUNE

Sk8r · 04/30/2015, 02:17 PM

A durso kit and a doublewalled downflow create a siphon break when the water is too low to flow over the teeth of the downflow box. No more water can reach the intake, siphon breaks, end of siphonage.

Siphoning is sneaky. You can create a real mess, eg, by having a pump with an outflow hose sitting in the bottom of a pond. If the pump is cut off, but the hose is full and has its end sitting lower than the pond---the hose will continue to drain the pond until it reaches the level of the pump intake.

If you have an autotopoff and let the outflow hose ever reach too near the water of your sump, while the ATO reservoir sits lower than your tank, you will equalize the salinity between the two tanks. How? ATO pump detects a low water condition, pumps fresh water in. HOse is touching water now due to water rise to meet it. HOse flows backward, delivering salt water to the ATO reservoir. Lowering water level.
The ATO pump detects a low water level. Cuts on. Delivers more water, up to level of hose. Hose siphons backward, etc. Eventually your tank and the ATO are the same WAY too low salinity and you're in trouble.
Been there. Done that. Caught it in time. Passing the tee shirt on...

On the other hand, while in a pure-water system the answer might be a check valve to prevent backflow---do NOT do it in a living tank or system with calcium involved. It will freeze due to calcium and it will create a disaster.

Sgt Jonny Cat · 05/02/2015, 04:14 PM

Thanks Sk8r...appreciate the input...

RocketEngineer · 05/02/2015, 06:11 PM

Siphon break holes are ok but over time they will clog. If you forget to clean them, you no longer have that feature.

The only absolutely safe methods I know of are ones that don't require any maintenance. For the return it means having enough room in the sump for everything that drains out of the display until the outlets pull air. This is helped by having the outlets near the surface. On the drain side, the only sure fire way to make sure the tank doesn't overflow is to have a DRY emergency drain line that can handle the entire return flow at full siphon. This will flush and then pull air therefore be very noisy and alert you to a problem.

Siphon break holes are a nice idea but I feel they provide a false sense of security. Only by having the outlets themselves pull air do you ensure that the sump won't overflow.

JMO.

Sgt Jonny Cat · 05/07/2015, 01:18 PM

Thanks for the input Rocket, but if you notice in the video, I have the breaks at water level so I can always see at a glance that water is still shooting out of them. Also, I drilled 2 of them just in case that snail decides to cover one at the wrong time I still have a back up. Works pretty well so far...

Shawn O · 05/08/2015, 08:54 AM

I was thinking the same thing regarding twin holes.

04/30/2015, 12:54 PM	#1
Sgt Jonny Cat Registered Member Join Date: Mar 2014 Location: North of Boston Ma. Posts: 685	How to hopefully prevent your tank from over flowing (video) Hi guys, I just wanted to share this one with you all. It's a video that discusses siphon breaks in your return line... Enjoy!! https://www.youtube.com/watch?v=s10VX0dYUNE __________________ In the process of putting together a 150 gallon mixed reef. Ill keep you posted. Current Tank Info: 55 Gallon

04/30/2015, 02:17 PM	#2
Sk8r RC Mod Join Date: Feb 2006 Location: Spokane WA Posts: 34,628 Blog Entries: 55	A durso kit and a doublewalled downflow create a siphon break when the water is too low to flow over the teeth of the downflow box. No more water can reach the intake, siphon breaks, end of siphonage. Siphoning is sneaky. You can create a real mess, eg, by having a pump with an outflow hose sitting in the bottom of a pond. If the pump is cut off, but the hose is full and has its end sitting lower than the pond---the hose will continue to drain the pond until it reaches the level of the pump intake. If you have an autotopoff and let the outflow hose ever reach too near the water of your sump, while the ATO reservoir sits lower than your tank, you will equalize the salinity between the two tanks. How? ATO pump detects a low water condition, pumps fresh water in. HOse is touching water now due to water rise to meet it. HOse flows backward, delivering salt water to the ATO reservoir. Lowering water level. The ATO pump detects a low water level. Cuts on. Delivers more water, up to level of hose. Hose siphons backward, etc. Eventually your tank and the ATO are the same WAY too low salinity and you're in trouble. Been there. Done that. Caught it in time. Passing the tee shirt on... On the other hand, while in a pure-water system the answer might be a check valve to prevent backflow---do NOT do it in a living tank or system with calcium involved. It will freeze due to calcium and it will create a disaster. __________________ Sk8r Salinity 1.024-6; alkalinity 8.3-9.3 on KH scale; calcium 420; magnesium 1300, temp 78-80, nitrate .2. Ammonia 0. No filters: lps tank. Alk and cal won't rise if mg is low. Current Tank Info: 105g AquaVim wedge, yellow tang, sailfin blenny,royal gramma, ocellaris clown pair, yellow watchman, 100 microceriths, 25 tiny hermits, a 4" conch, 1" nassarius, recovering from 2 year hiatus with daily water change of 10%.

05/02/2015, 04:14 PM	#3
Sgt Jonny Cat Registered Member Join Date: Mar 2014 Location: North of Boston Ma. Posts: 685	Thanks Sk8r...appreciate the input... __________________ In the process of putting together a 150 gallon mixed reef. Ill keep you posted. Current Tank Info: 55 Gallon

05/02/2015, 06:11 PM	#4
RocketEngineer Space is big. Join Date: Feb 2007 Location: Maryland Eastern Shore Posts: 3,226	Siphon break holes are ok but over time they will clog. If you forget to clean them, you no longer have that feature. The only absolutely safe methods I know of are ones that don't require any maintenance. For the return it means having enough room in the sump for everything that drains out of the display until the outlets pull air. This is helped by having the outlets near the surface. On the drain side, the only sure fire way to make sure the tank doesn't overflow is to have a DRY emergency drain line that can handle the entire return flow at full siphon. This will flush and then pull air therefore be very noisy and alert you to a problem. Siphon break holes are a nice idea but I feel they provide a false sense of security. Only by having the outlets themselves pull air do you ensure that the sump won't overflow. JMO. __________________ -RocketEngineer "Knowledge is what you get when you read the directions, experience is what you get when you don't." - Unknown Current Tank Info: None Currently

05/07/2015, 01:18 PM	#5
Sgt Jonny Cat Registered Member Join Date: Mar 2014 Location: North of Boston Ma. Posts: 685	Thanks for the input Rocket, but if you notice in the video, I have the breaks at water level so I can always see at a glance that water is still shooting out of them. Also, I drilled 2 of them just in case that snail decides to cover one at the wrong time I still have a back up. Works pretty well so far... __________________ In the process of putting together a 150 gallon mixed reef. Ill keep you posted. Current Tank Info: 55 Gallon

05/08/2015, 08:54 AM	#6
Shawn O Registered Member Join Date: May 2014 Location: People's Communist Republic of Massachusetts Posts: 1,474	I was thinking the same thing regarding twin holes.