Adding a hole for herbie, few questions.

[LakeShow]

I have a drilled 65g tank with built in overflow box that has a 1/2" return and 1" drain through the bottom. There is not enough room to add another bulkhead in the box on the bottom panel so i plan to drill the back panel inside the overflow box for a 3rd hole that will be 3/4" for a full siphon herbie drain, and the 1" will be a backup.

My question is how far down the back wall should this hole be? Im not sure if im going to be able to fit any pvc in there so it will most likely be an open bulkhead for the siphon.

Has anyone set up their herbie drain like this? I would love to see/hear how you did it and if it works well for you or not.

My diamond bit and plumbing pieces should be here today, so looking for some quick tips on what to do.

Thank you

 

[uncleof6]

Is it tempered? If it is, you won't be drilling anything anywhere. Make sure first.

 

[LakeShow]

I asked the manufacturer and made sure non of the panels are tempered. Its a rimless tank with 3/8" glass all around with 1/2" bottom.

Is there any problem with this design though? Having the siphon out the back of the tank when the rest of the plumbing is through the bottom? And does the siphon need to have a 90 on the inside of the overflow box to prevent a vortex?

Also to save space i would like to remove the durso from the emergency overflow and just have it be an open pipe, any problems with this?

Thank you for any input.

 

[ReefPharmer]

That's what I did in my tank. I drilled 5 inches or so from the top inside the overflow box. Works well