How do I keep my sump from overflowing during powerloss?

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.

tmcpeek

Aquarium Advice Freak
Joined
May 7, 2003
Messages
414
Location
California
I have drilled the return fittings inside my overflows and it still siphons enough water to just overflow the sump. Any other ideas?

225 Gallon Tank with 2 built in corner overflows and a 29 gallon sump.
 
The only thing I can think of is get a bigger sump, or an overflow of some sort into another container. Or can you keep the water level in the sump any lower?
I have the same setup with my 210, but my sump is a 55 gallon. When I shut down it only fills about halfway. How do you shut down for maintainance?
 
Yeah, I was thinking of adding another sump to hold some of the additional water. For maintainence, I have a ball valve on my returns so I can stop the siphon. Just can't do it if the power goes out and nobody is home. I cannot lower the water level in my sump anymore.

As I was just looking at it I wondered if I turned the elbows inside the overflow so they are facing up teh water could not flow up hill. My only concern is that the return hose may kink. I will try it since the fittings are only a buck or 2. Thanks Kurt.
 
tmcpeek said:
Yeah, I was thinking of adding another sump to hold some of the additional water. For maintainence, I have a ball valve on my returns so I can stop the siphon. Just can't do it if the power goes out and nobody is home. I cannot lower the water level in my sump anymore.

As I was just looking at it I wondered if I turned the elbows inside the overflow so they are facing up teh water could not flow up hill. My only concern is that the return hose may kink. I will try it since the fittings are only a buck or 2. Thanks Kurt.

Not sure about that. Maybe you could use a big tupperware container and place you sump inside of it. This way if it overflows you have something to catch the water.
 
You could also lower the water volume in your sump at operational level. Short of that, you will probably have an issue.
 
Raise the level of the in-tank part of your overflow. This will lower the sump water level and also raise the level the overflow pulls from so it can't drain as much from the display if you lose power.
 
How far down does your tank drain? It should not be very much. If alot then maybe raise the return nozzles up until they are just under the surface of the tank water (maybe the return lines from your sump aren't breaking suction until the nozzles come out of water.......)
 
drill a small hole directly beneath the water line on your outlet. This will break the siphon so that you wont backfill your sump.
 
BearFan_ I unfortunately cannot lower the level any further. If I do there is hardly any water in the sump and I get air bubbles.

Indy-- How do I raise the water in the overflow part? I am guessing by throttling down the return pump so it does not pump as much water back in the tank.


Overstocker--- The return is about 3" lower than the bottom of the overflow slots. Are you saying I should put a 90 on them or something to raise them up higher?

Nitrate--- I did drill a hole in the return fitting inside the overflow, but it did not seem to do anything about siphon. Maybe I drilled in the wrong spot?

I am heading to the hardware store to buy some fittings to play around with. I will let you know how it goes.
 
Is this a hang on overflow? If so then they usually have slots where you can rase the intank portion of the overflow. Rasing that up will increase the water level i nthe tank. If its a tank with an internal overflow then the only way to rase the water level would be to block off the bottom of the overflow area.

On the returns that are 3" below the water level. When you power your sump off those returns become syphons back into the sump. They will continue to syphon until air can be introduced into the plumbing. By drilling small 1/16th" holes just below the water line on your return you will create a syphon break. This wont break the syhpon on your overflow! This will only stop the water from returning into your sump via your return lines. THe small holes just below the water line on the return will not affect the returns performance at all.

What I do is to find my maximum safe operating level of the sump. I fill the tank up till it just starts to flow into the sump. Then I start filling the sump till its about 2" from the top of the sump. Then I power on my pump. The water level will drop some as the water fills the pipes. Soon the water will start comming back the return lines and then mark the level of the water in your sump as the MAX RUNNING WATER LEVEL. And then slowly take water out of the sump till your pump starts taking on air. Mark that MIN RUNNING WATER LEVEL. THen keep the water level in the sump between those lines and you will be fine during a power outage. If you fill your sump full and you power on the sump and it runs the water level down till the pump starts sucking air and you have to add more water to the sump then your sumps to small.

What size tank do you have and what size sump are you running?
 
tmcpeek said:
Nitrate--- I did drill a hole in the return fitting inside the overflow, but it did not seem to do anything about siphon. Maybe I drilled in the wrong spot?

The hole doesnt go inside the overflow, it goes on the pump return into the tank. When the pump quits running the water thats is left in the tube running up from your sump to your tank quickly reverses direction and creates a siphon that in turn will drain the tank until the siphon is broke. The hole you drill will be on the return into the tank, and as FF stated it should be 1/16" diameter.

My first SW tank was a a great learning experience, I flooded my floor several times before I figured out where the water was coming from.

HTH
 
For a drilled tank the hole is in the line going from your sump pump to the tank. I have the hole drilled in the 90 and I keep my nozzle about a 1/2 inch from the tank water level. When the power or pump is turned off I here air sucking thru the small drilled hole but as soon as the nozzle breaks the top of the water then all water stops, no more syphon/trickle! I have a mega-flow style so my nozzle piping comes over of the top of the box so it is easy to keep the nozzle near the top of the water.
 
Thanks for all the help. I got it fixed. I drilled some holes and raise my return fittings with 90 degree elbows.
 
Other suggestions...

- you can add a check valve into the return line. This prevents water from flowing backwards into the sump at all. (These check valves have been know to fail....)

- The little hole in the return line, just below the water level can work but it has to be larger than you might think. Keep drilling a bigger and bigger hole....kill the power and watch what happens. At some point, the hole starts to allow so much air into the reverse-siphon that it stops.
 
Back
Top Bottom