New 150g. DIY Sump/Closed Loop with PreDrilled Holes Help

[trustemedia]

Sorry if asked 1000 times. I got a new 150g. It has dual overflows with 2 pre-drilled holes. It also has 3 holes drilled on bottom outside of overflow boxes (1 on the left, 1 in the middle, and 1 on the right). Told they drilled it to be a closed loop system they were going to set-up. The tank is new and was never set-up, just stored.

I have a 55 gallon I can use as a sump. Will be my 1st time doing a sump. With the 5 holes I have predrilled (4 in overflow boxes/2 each and the 3 extras on tank bottom/see pics) how would you go about setting this up?

I need some advice, suggestions, direction to get this started.

Thanks.

There is also a crack in the middle top trim (see center hole pic). I just noticed it today. Should I be worried about that at all? Apoxy? New trim? Reinforce braces with siliconed glass? ?

Crack in pic below:

 

[trustemedia]

No one knows anything about a crack in trim?

 

[trustemedia]

Or how I would go about plumbing this tank?

 

[FishEggs]

my 75gal top trim is cracked like that on the front and back side and i haven't had any adverse affects yet. Been that way for 6or 7 years now (ever since i got it.) As long as the center braces aren't cracked or broken i think it'll be fine.

As far as the plumbing goes are you setting up salt or fresh? Either way , sorry i have no experience with sumps.

 

[flyfishfan1966]

Sounds like you got three weird, extra holes

I have a 180 w dual overflows.
Each overflow has a drain out and a return back in.
I might plug the three extraneous holes and set the overflows and returns properly.
Remember the overflow rate is dictated by the return pump at head height.
You need the overflows in the towers to be set up correctly with glued PVC and proper bulkheads.
The returns can be set up any way you'd like with bulkheads and glued PVC.

Keep it simple !!! Less bends the better.

Let me know if you need more.

 

[flyfishfan1966]

Here's a pic of overflows