Overflow box questions (please help me)

Okay, I'm in the process of making a 30 gal sump for my 75 that I will be setting up soon. I am very uncertain of lots of things because I am not completely sure of how everything works. I have been following some build reads and also found Powermans sump/fuge thread to be helpful.
My question... My overflow box is on the back left corner of my tank. It is drilled. The holes are side by side. Is one hole for the water going to my sump, and the other for my return?
Or, will one flow to my skimmer section, and one to my fuge? Thus meaning I would use flexible tubing from my pump(Eheimm 900gph)to move water back into the DT. (I very confused)

Please help me with any helpful info. Right now I had planned on one being my return, while the other tees off to my skimmer/fuge sections with ball valves adjusting th flow to each one. I have olot o plumbing stuff that a friend has given me. I will try to get some pics up. Sorry for not having any on hand.

Please help me.

 

maybe these pics will help some as to indicate what i have (or am attempting to have) going on. i am sorry about the poor photo quality. i am without a camera and had to take the pic with my macbook.
thanks in advance for your help

 

my skimmer section is first, my return section is second, my refugium is last. i have plumbing teed off going into my skimmer section as well as my refugium. i have my other line going from return section to overflow box
nothing is attached yet, it is only pieced together. my baffles have not been added either however, i do have them cut.
thanks for your help

 

Sounds to me like you have got it.1 line for drain to sump/fuge and the other is the return.Sounds like your fuge is setup correct also.

 

thank you Doylef4i,
so it is correct that one comes out of the overflow box, while the other returns to the overflow box???

i am just being very cautious because i am weary of 90 plus gallons of water dumping on the floor or some freak accident happening. lol

i guess i just feel much more comfortable knowing 100% in full that what i am doing is correct and will not lead to disaster.

thanks again. feedback from any other members would be greatly appreciated.

JP

 

If both the holes are in your overflow box then it sounds like they are both drain lines. Probably just has dual drains rather than just one. Routing your return into your overflow is just going to pull the water right back out. You want your water returning on the other side of the tank so it can mix with your display water.

Use some of that piping to build a return line to the opposite corner as the overflow.

 

No both go to the sump from the overflow. The return enters the tank from over the side as far away from the overflow as possible. Tee one side from the overflow to send some to the refugium and the rest to the sump.

 

2in10,
thanks for your help (again)
one question... if i tee one of the lines so it runs to the skimmer section as well as the refugium, then where does the other line go to? which part of the sump? i am not understanding why if they are both drain lines how come i dont send one to the skimmer section, and the other to the refugium.
after teeing the one line off, what will i do with the other line that has not been teed?
thanks again
JP

 

i agree with 2in10 and takingvapes. you don't want your return coming back into your overflow. both holes are "exits"

 

i don't think that is what he meant. there is no reason to tee, send one to your fuge and one to your sump/skimmer.