over flow holes

[Reefdiver72]

What size bit should I order to drill my holes I am thinking i need a 2inch bulk head in my 75. My 120 has 2 though. Will one be enough or should I put two in my 75 also?

[szwab]

depends on the brand and type of bulkhead. Plat it safe get the bulkheads first then the bit. As far as how many: depends on the flow the tank will have through it. there is a calculator on the home page that helps a bunch.

[tye_c]

You can look at Savko's site to determine the hole size for the bulkhead you are using.

[RokleM]

From savko.com - SCH80 T*T - 2" (3 1/4" hole)

[hollback]

Like Eric posted. Go with the sch 80. You should only need 1 - 2" drain in your 75.

[Bowman]

FWIW My minimium drain size is 1 1/2" I also put in 2 drains for redundency if something should happen to the first drain the second one provides for a back up. This is especially important if you are going with smaller sized drains. IMO people usally undersize their drains and don't include multiples so if something plugs a single drain youre GOING to have water on the floor. Multiple oversized drains virtually elimanate that from happening. HTH

[lakee911]

belt and suspenders there, bowman :)

[szwab]

verry good point on the redundancy.

[Reefdiver72]

That is kinda what I was thinking 2 to play it safe I have 2 overflows on it now just because of that problem. I have an Iwaki 70 coming to run that tank the skimmer and possibly my frag tank.
I have a Iwaki 30 doing it all now but its not enough for what I want to do I think I will go with 2 2inch schedule 80 bulkheads just like my 120 is done with .
Thanks everyone for helping me decide that