Plumbing an internal overflow

[reelss]

I want to make an inexpensive frag tank. I got a 20 gallon long tank from petco and am planning to install an internal overflow like this one here:
https://www.ebay.com/itm/700-GPH-AQ...S/251968134208?hash=item3aaa789c40:rk:15:pf:0

How would the plumbing inside the overflow be? Is it just a single standing pipe? or a durso style one? I will be drilling in one hole only.

 

[CC13]

I want to make an inexpensive frag tank. I got a 20 gallon long tank from petco and am planning to install an internal overflow like this one here:
https://www.ebay.com/itm/700-GPH-AQ...S/251968134208?hash=item3aaa789c40:rk:15:pf:0

How would the plumbing inside the overflow be? Is it just a single standing pipe? or a durso style one? I will be drilling in one hole only.

You don't need an overflow box at all. Drill two holes in the appropriate size either in the bottom or side panel (whichever you prefer), install two bulkheads each with a strainer so no snails or fish can clog the pipes and your on your way.