[I would drill just as kwl1763 suggested. You can always cap, but you'll only kick yourself if you need or want those holes once filled.
Just a tip, be VERY specific on the hole size you need for the bulkhead you are going to utilize. I asked for holes to be drilled in my current tank for a 1.5" bulkhead . Instead I got a hole that was 1.5". You see bulkheads require a much larger hole than the actual flow-through deminsions. Now I'm stuck with three cheap 3/4" bulkheads because they are the only ones that will fit a 1.5" hole. Lesson learned, so be specific!!
My suggestion would be to find some nice, sturdy, rock solid bulkheads and drill to that specific size. They may cost abit more, but you'll sleep alot more soundly at night...trust me. I've already gone through several leaks, replacements and headaches with the cheapo black plastic ones you get locally like
these.
I would recommend something more like
this, or
here and click on Tank Fittings. Just like Marc mentioned, if a bulkhead fails you are either going to have to drain or your tank is going to empty itself to that level.
My details to maybe spur some thought...
The way I had mine drilled was based on the predetermined rockwork that I wanted. So, my returns are equally spaced 3" from the top of the tank across the back between the overflow and opposite side. The intake hole was drilled directly beneath the right side's return low enough to be concealed by rockwork. This gives a clean look and all you see are the returns.
The intake has a 90 so the strainer is parallel to the back glass. This gave me more room to move the rockwork closer to the back of the tank and still be able to access it for cleaning.
If you have any questions feel free to drop me a PM or post up!]
Edited By Modo on 1111447351
