Bottom-drilled tank hole is leaking

[Keysmash]

Hi,

I did not built this tank but got it with a sump connection already there. It's been working fine but I had to break it down and move it, and in the process one of the tubes (the one on the left) was knocked around, and when I checked, it's no longer watertight.

Can I seal it from the bottom? I can let it dry out but accessing it from the top, let alone all the cleaning I'd have to do, would be a nightmare. Failing that, would it be feasible to not clean the upper area and just put an enormous amount of sealant on top? The current overflow design only uses the top third.

 

[monkeyCmonkeyDo]

Wheres it leaking from? The bulkhead? The tank? The hose?
D

 

[JumboShrimp]

Just curious-- and maybe not the best route-- but is the leak so miniscule (like a single drop every several seconds) that salt-creep might stop it up within a day or two?

 

[DeepintheReef]

Hi,

I did not built this tank but got it with a sump connection already there. It's been working fine but I had to break it down and move it, and in the process one of the tubes (the one on the left) was knocked around, and when I checked, it's no longer watertight.

Can I seal it from the bottom? I can let it dry out but accessing it from the top, let alone all the cleaning I'd have to do, would be a nightmare. Failing that, would it be feasible to not clean the upper area and just put an enormous amount of sealant on top? The current overflow design only uses the top third.

The issue is likely the Teflon tape on the bulkhead. It does nothing to help seal the tank as the rubber gasket inside the overflow is what makes it watertight when the outer ring is tightened against it.

Yes, it’s a pain but I would drain enough water in the tank so its below the overflow. Drain the overflow and give it a decent vacuum with a wet/dry. Clean the glass where the bulkhead will go. You can normally do a good enough job by sticking your finger up through the glass hole from the bottom with a rag and wiping away all debris. Failing to clean the overflow area and just putting sealant on it, will just seal over the dirt already in there and likely not be waterproof.

Once clean, you may be able to use the same bulkheads and gaskets, but theyre cheap enough to replace with new.

 

[Keysmash]

Unfortunately, the leak is a steady trickle, and it's freshwater at the moment so no salt at all.

The area is currently drained, though it'll take a while to completely dry out. But it's got fine sand in there, and it's in the corner of the wall, and it's incredibly heavy to move - that's how it got damaged in the first place.

If you recognize it, is it that it can be unscrewed from the bottom to get access to the hole and clean it out? Like I said, I have no idea how it was put together originally. It connects to a PVC pipe.

 

[DeepintheReef]

Unfortunately, the leak is a steady trickle, and it's freshwater at the moment so no salt at all.

The area is currently drained, though it'll take a while to completely dry out. But it's got fine sand in there, and it's in the corner of the wall, and it's incredibly heavy to move - that's how it got damaged in the first place.

If you recognize it, is it that it can be unscrewed from the bottom to get access to the hole and clean it out? Like I said, I have no idea how it was put together originally. It connects to a PVC pipe.

Yes, it will unscrew from the bottom. Typically the two pipes that stick into them inside the overflow are not glued in but only pressed in. You should be able to unscrew the ring that is up against the glass and lift out the piece after disconnecting the hoses below.

 

[DeepintheReef]

Also, it doesn’t need to be completely dry. Just wipe the glass inside the overflow with a rag once the bulkhead is removed to make sure there is no dirt or debris between the gasket and the glass.

 

[Chefwheredyougo]

Be very careful when removing the bulkhead. Sometimes they can be a **** to get off, and if you aren't careful you can crack the glass.

 

[Matt L.]

Do you have aquarium silicone on hand? If you cannot get the bulkhead to seal, you can silicone it in place. This is a solution of last resort, as it fixes the bulkhead in place and it would have to be cut out, which is a labor intensive and messy process. This is not recommended for plumbing that can be jostled or moved, as it can break the silicone seal. If you can clean (and most importantly dry) around the bulkhead on the top, a bead of silicone around where the bulkhead contacts the glass may stop your leak. I can't tell from the photo where the leak is coming from.

Good luck,

Matt

 

[Keysmash]

I have tried to unscrew the bulkhead but it only turns in either direction until the PVC pipe above bumps into the glass. I think they may be glued together. Short of trying to saw through the bulkhead below I'm not sure I can get it off.

When the water comes out the sides of the glass hole, it runs down the outside of the tube attached to the bulkhead but then drips at the low point. If I take another, larger tube and put it around that one and glue it to the glass above, so that there's no direct water pressure to push against that seal, do you think it would safely direct any excess into the sump if the bulkhead seal fails again? The overflow section of the tank only holds a few gallons.

 

[DeepintheReef]

Do you have a second wrench to hold the pipe sticking under the tank while you try to turn the nut?

 

[Chefwheredyougo]

If you can, get some PVC cutters and nip it off. I had the same issue and had to use wire to saw it off because of the way my tank sat on the stand, there was no way to get it off short of draining the entire tank. Using wire to saw it off was the easiest and safest solution I could find after trying for weeks.

 

[Sshannon]

Sometimes the bulkheads are reverse threaded. So its the opposite of righty-tighty, lefty-loosy