I used a 2" bit on my 1" sch80 bulkhead. I think stats call for a 1 7/8" bit, but 2" worked just fine for me. Schedule 40 Bulkhead 1", hole size 1 3/4
Yes, I am about to quite Mr Saltwatertank Terrible Advice Tuesday post, but it was a good explanation when he posted it on FB not long ago.
"Aquarium bulkheads come in two flavors:
- sch40
- sch80
“sch” (short for “schedule”) refers to the thickness of the plastic used in PVC plastic parts. The bigger the schedule, the thicker the plastic and the more pressure that the pipe can hold. It makes sense then that a sch80 bulkhead is beefier than a sch40 bulkhead. Usually a lot beefier.
Take a look at the picture of the two bullkheads. The black sch40 bulkhead is on the left and the gray sch80 bulkhead is on the right. You can clearly see how much beefier the sch80 bulkhead is than the standard sch40 bulkheads supplied with most aquariums. Also note how much thicker the rubber gasket is.
While the sch80 bulkhead is beefier, the added strength isn’t needed around saltwater tanks. The pressure in an aquarium PVC pipe is very low and you won’t even get close to blowing out a sch40 bulkhead or pipe. Also note that if you break a sch40 bulkhead, you are over tightening it or putting too much pressure on the bulkhead with the attached pipe. In other words, you’re doing something wrong!
If the added strength isn’t needed why do hobbyists use sch80 bulkheads? Sch80 bulkheads are used when hobbyists are looking for a beefier look or are using sch80 pipe (again not needed) and want to maintain the all-gray look. Basically, it’s a matter of taste.
Oh, if someone tells you that you have to use sch80 bulkheads or else you'll have leaks, let me know so I can add it to my "Terrible Advice Tuesdays" posts!"

Yes, I am about to quite Mr Saltwatertank Terrible Advice Tuesday post, but it was a good explanation when he posted it on FB not long ago.
"Aquarium bulkheads come in two flavors:
- sch40
- sch80
“sch” (short for “schedule”) refers to the thickness of the plastic used in PVC plastic parts. The bigger the schedule, the thicker the plastic and the more pressure that the pipe can hold. It makes sense then that a sch80 bulkhead is beefier than a sch40 bulkhead. Usually a lot beefier.
Take a look at the picture of the two bullkheads. The black sch40 bulkhead is on the left and the gray sch80 bulkhead is on the right. You can clearly see how much beefier the sch80 bulkhead is than the standard sch40 bulkheads supplied with most aquariums. Also note how much thicker the rubber gasket is.
While the sch80 bulkhead is beefier, the added strength isn’t needed around saltwater tanks. The pressure in an aquarium PVC pipe is very low and you won’t even get close to blowing out a sch40 bulkhead or pipe. Also note that if you break a sch40 bulkhead, you are over tightening it or putting too much pressure on the bulkhead with the attached pipe. In other words, you’re doing something wrong!
If the added strength isn’t needed why do hobbyists use sch80 bulkheads? Sch80 bulkheads are used when hobbyists are looking for a beefier look or are using sch80 pipe (again not needed) and want to maintain the all-gray look. Basically, it’s a matter of taste.
Oh, if someone tells you that you have to use sch80 bulkheads or else you'll have leaks, let me know so I can add it to my "Terrible Advice Tuesdays" posts!"