Help with Sump Design

[Morpheus_01]

Hey there,

I am designing a sump for my 90 gal RR.

-Sequence 3600Pro12 3000gph @ 4' head
-Custom PM Bullet dual beckett 31.5" High with sump
-1" durso Standpipe from internal overflow
-draining with a straight pipe directly throgh the top of the sump 2" below waterline
-the pump will divert 1000 gph to the beckett and 700 gph back to tank circulation (based on 700 gph durso rating) (correct? or wrong?)

Thank you for your input and criticizms.

[Dman]

M1,
Just make sure there is enough clearance in the mixing box of the PM skimmer to handle the 1.5 inch submersion, otherwise it could back up on ya.
Otherwise looks good to me.
Dman
:spin:

[Morpheus_01]

The skimmer is a clone of the Precision Marine Bullet dual beckett and is a sealed unit. It has 2 1" intakes for the beckett's and an 2" output to the Sump.

[Dman]

M1,
The water level inside the mixing chamber will equalize with the water level in the sump if the output is submerged.
Dman

[Morpheus_01]

So are you saying that the skimmer should be elevated if the ouput is below the water line?

OR if the skimmer is level with the sump that the output of the skimmer should be just above the water level to prevent any backwash?

Won't 1000gph be sufficient pressure to prevent any backwash or are you saying that the output's 1.5" submersion in the sump to cut back watersplash will create too much back pressure?

Thank you in advance.

[Dman]

M1,
Regardless of the pressure, the water level in the mixing box will equlalize withthe ater level in the sump ONLY if the outlet is submerged. As long as the top of the mixing box is above the water level in the sump, you'll be ok.
Example:
If the mixing box is 12*12*16H and the water level in the sump is 19 inches the water level in the skimmer will be 3 inches above the level of the mixing box and into the foaming tower. Not how they're supposed to be run, makes them less effecient.
Solution:
Raise the skimmer a minimum of 3 inches, or lower the water level in the sump 3 inches.
As for the pressure, if anything the pressure will cause the water to rise in the foaming tower before it pushes out through the gate valve.
HTH
Dman
:spin:

[Morpheus_01]

If I place the skimmer return above the water line but I put a 90 deg elbow on the inside of the sump to place the water flow below the waterline to reduce noise, will it work? My cabinet is 33" high and the skimmer is 31.5" H and there isn't any room to raise the level.

Thanx

[afss]

If you have any plans of adding a refugium to this at a later point, you may want to take that into consideration now.

Scott

[Dman]

M1,
In a word, no. Doesn't matter what plumbing you install in the sump the water will always equalize, even if it has to go through half a kilometer of elbows.
For example:
Take a small bucket and punch a hole in the side of it. Submerge said bucket in a larger bucket of water and observe the water level in the smaller one. The smaller bucket is in effect your skimmer and the larger bucket your sump.
Now install piping with a 90; first on the outside of the small bucket, this would simulate a 90 degree bend in the sump and submerge. Then on the inside of the small bucket, this would simulate a 90 degree bend inside the skimmer (BTW, there should be a 90 inside the skimmer anyway) and submerge. Observe the results. The water inside equalized itself with the water outside.
Sorry, hard to screw with the physics on this one.
Has the skimmer been built yet? You could modify the design of the skimmer. It would be easier than trying to bending one of Newtons Laws (I'm making that up, I have no idea if it is one of Newtons' Laws)
Dman
:spin: