Modifying a stock overflow question

[Scoot]

I have a single-bulkhead overflow box, with the standard j-tube. No brand on the overflow, its just black acrylic on the inside, clear on the outside box. The outside box is deeper than most - a good 10" deep.

I've added a second j-tube to increase overflow rate, but I know I'm limited by the single 1" bulkhead.

If I replace the bottom plate of the outside box, with a DIY piece with 2x1" bulkheads, would I be getting the typical 1200GPH that most of the new ones claim to offer?

I'm working on increasing flow in my minireef to 10 times turnover, and the overflow is the first step... (wouldn't want to add a 1100GPH pump with a 350GPH overflow

 

[afishyonados]

Why are you increasing the flow through the sump? Wouldn't less contact time retard the beneficial effects the sump based filtration could provide?
Would a closed loop system be out of the question?

Your idea of modifying the overflow would work.

 

[Scoot]

Dr. J from WWM, and everything else I've read indicate I should have 10 times flow in a mini-reef... he indicated NOT to include powerheads, so I'd think a closed system wouldn't count either (???)

he suggested that I strive for 750GPH through the sump.

Where else am I'm going to increase flow?

 

[afishyonados]

The closed loop would not take up any room in the tank, and would not add any heat to the tank, unlike a powerhead.
If you are using a Blueline 40 with 3/4" piping, you can increase the water flow dramatically without retarding the filtration in the sump. If you move too much water through the sump, the skimmer/refugium will not be near as effective.

 

[Scoot]

So a closed circuit like that, just pumping water from one side to the other, counts towards the 10-times water turnover?

Again, the guys at WWM suggested I push towards 750gph through the sump, even after I explained that at 400gph or so, it seems like a LOT of water going through there.

 

[afishyonados]

That is way too much water through the sump.

The closed loop would draw water out of the tank, into the pump, then back into the tank. I typically split the return with a tee, and split those again in the tank with a tee, then a 90 degree elbow on the end. This gives you four outputs, and if you do not glue the tee or the elbow, you could manipulate the direction of the output.