Drilling 180

[hdking]

Is there a magic formula that tells you how many holes you can safely drill? I'm planning on drilling 5 holes in my 180 for a closed loop system but before I start I wanna make sure the tank will handle it. All holes on back panel of course. Thanks

 

[Jpugh73]

I drilled 7 holes in the back of my 125

 

[hdking]

What size bulkhead? Mine will be 1"

 

[Jpugh73]

Mine are 1in also. I just made sure to not drill to close together or the edge at least 1 bulkhead length from edges