Overflow and Sump Question

Maverick00 · #1 04-05-2011, 01:20 AM

it all depends on quite a few factors

-how high you run your water level above the overflow inlet
-how much pvc you are running
-where your siphon stop hole is located on return nozzles

Id recommend running sump as low as you can and simulate a power outage, then you mark out how much higher the level has raised and adjust accordingly

for an example on my 33gal, ill lose only a few gallons back into the sump if the power goes out.

e46er · #2 04-05-2011, 01:34 AM

i have 5 gallons or so flow into sump when the return pump shuts off

Leon71 · #3 04-05-2011, 02:26 AM

I read this somewhere on the net, just not sure where.

Fill your display tank until it starts to spill into the overflow and down into your sump. Fill sump until 1" from the top. Start the pump and wait for everything to level out. Mark this level on the sump with a marker or tape that won't come off easily. This is your absolute top level. Do not fill beyond that line. All is good.

Leon

Maverick00 · #4 04-06-2011, 04:33 AM

Quote:

Originally Posted by Leon71

I read this somewhere on the net, just not sure where.

Fill your display tank until it starts to spill into the overflow and down into your sump. Fill sump until 1" from the top. Start the pump and wait for everything to level out. Mark this level on the sump with a marker or tape that won't come off easily. This is your absolute top level. Do not fill beyond that line. All is good.

Leon

i was just thinking about this technique which is a great baseline. However IF you have your intake nozzle/s a few inches below the waterline or more make sure you have a "siphon stop hole" near the surface. When you first fill your display tank up to the overflow all is fine and dandy, until you turn on your return pump which will create a back siphon to your sump if the power should cut out. If your running a small sump with a large display tank combined with lower than waterline returns, a 1" safety net may not be enough. Just something to think about..

Leon71 · #5 04-06-2011, 01:46 PM

Maverick,

Well spotted. I didn't allow for getting down to the siphon break. Thanks for adding that.

Leon

Sunee · #6 04-06-2011, 04:15 PM

Placement of the siphon break is crucial. I have also read somewhere that 2 siphon breaks are a must.
I am testing a new system - also with a small sump and have found I have to curve the loc line up so that the siphon break is just barely below the water line to prevent sump overflow.

Baldy · #7 04-07-2011, 11:51 PM

So i guess the amount that flows after the sump pump stops would depend on how much the water level is above the lowest point on the overflow intake. and that would probably depend on how much flow was going through it. anyone with cpr overflows (or others) can tell me how far above the bottom of the grooves of the intake box there water level sits when the pump is running?