Another sump question...

[edub]

I've been reading extensively and haven't found a good answer for this -
How does one make sure that the sump doesn't flood or run dry? I understand the constant level siphon but that's when the water levels are equal. With a sump below the tank, the water will run down until the end of the siphon is no longer in contact with the tank water. If the sump pump is too fast, the sump runs dry. If the pump is too slow, I imagine flooding could result.
Are the pumps always on or do they run when needed??
Am I thinking about this properly??
Any insight would be great.
Thanks

 

[nm reef]

To a certain point your concerns are legitimate.....
Most systems use a overflow of some sort...either hang-on or built in...to remove water from the display and transfer it to the sump. A overflow will have a maximum GPH ability. The water moves into the sump and it is pumped back to the display at a slightly slower rate than the maximum GPH of the overflow. As water enters the display it flows into the overflow and back to the sump...creates a loop that should balance outas long as the water coming in is not more than the overflow can remove. To prevent flooding of the sump just insure the pump can handle the flow rate from the display and in the case of a power outage you need to insure there is a syphon break to stop the water coming from the display and that the sump can handle the amount of backflow created due to the power outage. Sounds complicated but its really not...for additional information and even some graphic descriptions of sumps in action I'd urge you to serach here on this site as well as on-line for additional info....