Mr. Saltwater Tank

Terrible Advice Tuesdays: The Leaky Bulkhead Fix

Terrible Advice Tuesdays: To ensure your bulkheads won’t leak, glue them to your tank with PVC cement.

The rest of the story: Bulkheads (also known as tank adapters) are specifically designed to form a water tight seal with your tank when they are properly installed.

Proper installation instructions include:

  • making sure the mating surface is clean
  • putting the rubber o-ring  between the flange and tank (not between the tank and the nut)
  • making sure the hole is the proper size for the bulkhead (if the hole is too big, then the bulkhead will likely leak)

Notice how there is no mention of PVC cement in that list? That’s because it isn’t needed! Also, if you do glue your bulkheads in place, the only way to get them out will be to cut them out piece by piece. This will be a big PITA and could ruin your tank as the bulkhead will be permanently installed.

PVC glue is for plumbing parts, not for bulkheads.


Browse the Store! Questions?

Comments for this article (6)

  • Don Davis says:

    I guess this is a matter of how you interpret it. As you say Mark installing the bulkhead should always be done without chemicals or adhesives. However, for attaching PVC to a bulkhead I certainly glue in pipe to the inside of the bulkhead using PVC cement. To fix a bulkhead you do have to cut out the bulkhead and reattach. The one suggestion I would have there is use flexible spa PVC in the final part of the run up to your tank and a Union.

    With unions I have replaced bulkheads in the past in less than 30 mins because I just drain the water from the overflow in my tank or lower the water below the bulkheads. Use my reciprocating saw to remove the old bulk head and quickly install a new one. Simple, clean and fast.

  • Marine Hobbyist says:

    This is another one of those pieces of bad advice that constantly pop up on FB. Usually it’s “slap some silicone on it if it’s leaking” instead of cement but, exactly as you state, if it’s installed correctly, it needs nothing

    It’s usually the same people who say tap water is fine, you can’t have too many fish, a vlamingii is fine in a 60 gallon if it’s small, crowd!

  • Jay says:

    I would add the instruction:

    Hand tighten as much as possible, then a 1/4 turn more with a wrench. Many leaks happen because of over-tightening.

  • Laurie says:

    OOOOOOh NO! lokks like I’ve goofed, with silicone.

  • Barney Iott says:

    I am dealing with just this issue on a used acrylic tank i purchased. I have the tank buffed out and looking sweet but the bulkheads for the drain and return are glued in and I am not sure of the best way to go about removing them so I can put in new ones?

  • Ronald says:

    One other thing I personally recommend is using schedule 80 bulkheads over schedule 40 if possible. I’ve had terrible luck with schedule 40s cracking even being extra careful tightening fittings into them. Not so much of a problem if gluing fittings, but then in some cases you have to cut if you need to replace.

Comments are closed.