What size bulkheads?

[Polyp Addict]

Need a little help, I picked up a tank with no plumbing, and this will be my first attempt to do all the plumbing on the tank. I'm just lost at which bulkhead size I'm suppose to buy. I measured the diameter of the hole, it's a little over 1.5". Any help would be appreciated.

 

[Brew12]

Need a little help, I picked up a tank with no plumbing, and this will be my first attempt to do all the plumbing on the tank. I'm just lost at which bulkhead size I'm suppose to buy. I measured the diameter of the hole, it's a little over 1.5". Any help would be appreciated.

That looks like a 1 3/4" hole to me, so you would need a 1" bulkhead.

 

[Polyp Addict]

That looks like a 1 3/4" hole to me, so you would need a 1" bulkhead.

Thanks and would you recommend using unions? Don't know much about plumbing, but kept seeing them on youtube videos that people say to use

 

[Brew12]

Thanks and would you recommend using unions? Don't know much about plumbing, but kept seeing them on youtube videos that people say to use

I highly recommend using unions. They aren't necessary but it gives you a way to make the system easier to install, modify, and repair. It's just an easy way to divide your plumbing into sections.