System Test Failed Leaks


Spent my weekend installing plumbing (my husband helped!). Gave everything time to dry. Started adding water and 3 out of the 5 bulkheads are leaking. I read that they needed to be hand tight and I thought they were tight, but I have drips.

It won't be hard to fix the one on the sump, but the 2 on the tank are in a really tight spot. The stand was re-constructed using 2X4's and there is not much room. I siphoned the water out of the overflows and the sump until I get home tonight.
I still don't know if the return system leaks, I didn't get that far.
After I fill everything, do I turn on the pump? Right now I just feel defeated. I'll re-group today and start again tonight.


Active Member
What side are the gaskets on? They should be on the flanged side, not the nut. There's no way to stop water from leaking out through the threads.


Additionally, if you have it hard plumbed and the pvc is even just a tad long or short to the bulkheads you could have a slight gap even if the position of the gasket is correct. So be sure to check and see if you have gaps. Easiest to spot from the underside.


did you use silicon?
When I installed the bulkhead on my tank, I used rubbing alcohol to clean the glass and gaskets before applying the silicon.
No leaks.
Use only aquarium safe silicon.


I put the gasket in correctly, it just wasn't tight enough. My husband made a special tool so he could tighten it. All the leaks on the drain system have been corrected. When I started the return there is a leak, but all I need to do it tighten it after I drain the system.

I tried the flood test and nothing overflowed. I just need to get some baffles cut and installed in the sump so the skimmer will work.
I wish the butterflies would go away. I had a few flooding issues with my 75. I'm so thankful that my husband is helping, I could not do this without him.
Thank you all for your help!


Active Member
We ALWAYS get leaks when we start up a new system. Always. Like you found out, the hand tighten part is a guide line and where you should first stop. We then fill with water and watch for the leaks and just tweak a little and tweak a little until the leaks stop. I'm talking just a little nudge at a time. We use a big ole crescent wrench (or "water pump pliers" or "slip-joint pliers"). We plumb a lot of tanks so we invested in one. It's a god sent.
Bulkheads were made to be used without silicone. If you adjust them properly they will not leak.


Well-Known Member
Did you know to turn the gaskets themselves around where the two rings on one side of the gasket touch the glass, not the plastic of the bulkhead? The rings are there for the seal. Most manufacturers ship the bulkheads with the gasket turned upside down to prevent damages.