Drilling for bulkhead questions

[Jon Fishman]

I want to drill my acrylic tank to put in a bulkhead to act as the return (from pump in sump back to tank)

It’s a 3k gph pump, sump is in stand under tank, so 4’ or so..... I have the bulkhead and it will all be plumbed with Sched 40 pvc, 1”


So. I want to drill it on the back panel. without knowing the precise waterline, can I just drill it a little low to be safe? I have a back-flow fitting thingy to keep it from overflowing the sump in the event of pump failure.

I pre-drilled a scrap piece to ensure proper fitting etc. It’s 3/4” Acrylic...... should I just stay 5-6” away from a corner, and how far from the too euro-bracing?

Thanks

 

[CaliReefs]

I typically stay 6” away from the corners when drilling for bulkheads. Keeping in mind the front of the bulkhead has the lip. Remember to drill slowly and in intervals because Acrylic gets hot and the heat can degrade the structural integrity of the tank panel.

 

[Jon Fishman]

I typically stay 6” away from the corners when drilling for bulkheads. Keeping in mind the front of the bulkhead has the lip. Remember to drill slowly and in intervals because Acrylic gets hot and the heat can degrade the structural integrity of the tank panel.

What do you mean by “lip”? Since there is a gasket, and it is hand tightened, a round hole anywhere safe will be fine right?

Also, should I be more concerned about how shallow/deep to make the hole vs the waterline? I can only guess at the waterline right now

 

[CaliReefs]

The waterline is typically one or two inches below the overflow box teeth. But that varies depending on the return pump flow rate.

I keep return line bulk heads below the water line for a wide flow. The only time I drill the euro bracing is when using a variable section return for random flow.

 

[CaliReefs]

Can you post pix of your tank? That would help me offer a clearer answer to help you if possible

 

[Jon Fishman]

So I started adding water, to start some rocks etc, before the idea of drilling this happened! Either way. Here are some pictures

 

[Jon Fishman]

Can you post pix of your tank? That would help me offer a clearer answer to help you if possible

Kinda blurry/reflection etc but hope that helps

 

[CaliReefs]

Perfect. My advice would be to drill 3” below the teeth of the overflow box. Meaning the top of the bulkhead would be below the line of the teeth. That should help reduce splashing in the case you don’t plan to have additional pipe in the tank etc....

 

[Jon Fishman]

Will do! Thanks!

Perfect. My advice would be to drill 3” below the teeth of the overflow box. Meaning the top of the bulkhead would be below the line of the teeth. That should help reduce splashing in the case you don’t plan to have additional pipe in the tank etc....

 

[CaliReefs]

Nice tank!!

 

[Jon Fishman]

Just to be sure...... The overflow on the back is being plumbed for bean-animal. the external box is level with the tank top. So technically the waterline may be above the teeth? This is it with teeth removed