What makes a sump overflow

[xlayedoutx]

I've got a mega flow sump model 3 and was wondering what makes a sump overflow. I've heard people talk about it before but never say what caused it. Just asking so I know what to watch out for.

 

[reefnetworth]

bulkhead or skimmer box? need to know, to determine cause.

 

[kau_cinta_ku]

most of the time is that they have the sump to full and if any of the return pumps shut off the water will go down the return line until the siphon breaks. a good way around this is to add a check valve on the return line and also drill a small hole about 1/4 inch under the water where your return line goes into the main tank.

 

[xlayedoutx]

Now you have me lost. Whats the difference between bulkhead and skimmer box. My skimmer is located inside the sump if thats what you were asking.

 

[ApolloDog]

Let me give an example to see if it helps. Lets say you have an overflow that sends water to the sump (assume tank is drilled and you have a built in overflow chamber). So the water tumbles down into the overflow. Once in the sump, the water will eventually be pumped back up and enters the tank through some sort of nozzle or in my case, a 3/4" sea swirl. When the power stops, the water will continue down to the sump via the overflow, until of course the water level in the tank is low enough not to tumble into the overflow. Now if your return line from the sump to the tank is placed lower than your overflow (the actual ouput nozzle in the tank), the water will continue to backflow into the sump through that route, until the siphon is broken. Does this make sense?

Bottom line; in the case of a power outage, the tank will drain through whatever route it can find to the sump until it is low enough to stop. For this reason, you need to run you sump with enough space to handle the extra volume when the pumps are off.

Hope this helps.

 

[xlayedoutx]

That helps very much. Thank you.