will this work?

[latazyo]

since my tank is now empty, I figured now would be as good a time as any to add any holes that may need to be added

since I have my mag 12 cut back to about 50% I thought maybe I could add an additional drain

here is where the current hole is

I have already determined that there is not enough room to drill another hole on the bottom, so the other option would be to drill the back of the tank inside the overflow box

here is a graphic, the current setup is all in green and the new setup would be the red portion...I dont have enough room in my overflow box for an additional durso, so this would have to be a straight hole drain....

according to the RC calculator, at 1200 gph (which my pump would make at maximum capacity at 0' head, so in real life it is actually less) I would need 18 linear inches of overflow and 1.43" of drain diameter (1.6 sq inches of cross sectional area)

I have 18 5/8" of linear overflow space and dual 1" drains (1.57 sq inches of cross sectional area)

so I would be long on the overflow and short .03 sq inches on the drain size

this should work, even though the drains are at different heights...wouldnt the bottom (red) drain do all it can and eventually be overwhelmed, so the water level will rise and be taken care of by the existing durso (green)?

 

[latazyo]

just thought of something

would it be easier and better to just make the existing hole bigger?

is that even possible?

 

[scbadiver]

Yes. Very possibly and probably much better choice for strength too. I'd go 1 1/2 inch and call it good. (I have a hole saw)

 

[bigmayreefer]

definately just make the hole bigger- 1.5 or even 2 inch. I think the biggest you can fit considering the space needed for the bulkhead would be best. I dont think you can over drain a tank with your setup- although you can over fill.

 

[DrBDC]

I have a 4 1/2" hole saw. Go big or go home! :lol:

 

[Im Lon 2]

Yes make you can make the same hole bigger.

One thing to keep in mind.. Is your overflow box is big enough to haddle that much water? I would think so.. But not that much more.

My drains are big enough but my overflow box is to small to haddle that much water. In order for my flow to be all the way up the water goes over the top of the my overflow box.

 

[latazyo]

according to the RC calculator, I have enough overflow for 1200 gph...double what Im using now

 

[bigmayreefer]

if u needed more overflow you can make bigger notches too- if it becomes an issue

 

[DrBDC]

1200 actually might be too much through a 37 gallon tank!! :eek1:

Actually if you go much more than about 10% of your skimmer feed you decrease the efficiency of your skimmer. And unless you're using a beckett or downdraft that is very easy to do. I'd go with the bigger hole just for extra safety but you don't need to go crazy on it.

 

[latazyo]

roy, 1200 would only be achieved if the pump were running perfectly efficient at 0' head...which is obivoulsly impossible...not to mention that I have about 4' of head and several elbows and cut it down to dual 1/2" outputs

I just want to be able to use the pump at more than 50% capacity

if I added the CL then I'd be up there.....right now Im at 48X turnover, but the goal here would be to get the seios out of the display

 

[DrBDC]

I'd drill a cl intake and keep it seperate from the sump circulation/overflow box.

 

[Im Lon 2]

<a href=showthread.php?s=&postid=9256387#post9256387 target=_blank>Originally posted</a> by DrBDC
I'd drill a cl intake and keep it seperate from the sump circulation/overflow box.

definitely.. Your over flow.. I don't think will be able to handle the flow.

 

[Im Lon 2]

I'm at 39-40x turnover... And I want more

 

[latazyo]

decided to go with the 2" bulkhead and no closed loop

this is only a 37g tank, so the seios will remain and the drain will rock out at 2"

thanks for the input gents