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new tank with a leaky bulkhead, please advise

Beignet

Beignet

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Dear BAR members,

I recently purchased a 60 gallon, rimless cube tank. It's new and was drilled through the back wall to accommodate 3 bulkheads, 2 return lines (1/2") and a center drain line (1 1/2"). The tank passed all leak tests and ran for 2 weeks before a small leak started outside the tank, between the tank wall and the nut on the drain line bulkhead. I happened to be sitting next to the tank so caught the leak within minutes preventing a big mess. The leak wasn't slow, it was a drip rate of about 2 drips/second.

Of course, I called the store where I got the tank and they said that this shouldn't be happening. I agree, but it is. So, suggestion one was to loosen the bulkhead, inspect the gasket, retighten and retry. I did this and had an instant leak. Next advice, and where I currently am in this process, was to cut out the bulkhead and replace it with a new one. I cut it out and at that point noticed quite a messy hole. The hole saw did not make a clean cut and at the bottom of the hole, on both the inside and the outside of the tank, there is a tapering in the cut forming a bit of a slope downwards on both sides of the tank. The slope is still under the gasket, but it just doesn't seem quite right.

So, my question. Should I try a new bulkhead, worrying about a possible leak in a few weeks but hoping for the best? Or, should I insist on an entirely new tank? I don't have a sense for how likely it is that the original bulkhead was faulty or how much the quality of the drill hole matters and if this is a possible explanation for my leak.

The drill hole is also actually quite a bit larger than the bulkhead fitting. I didn't perfectly measure this, but there is a space of about 0.25cm between the tank hole and the bullhead fitting all the way around. I'm wondering if this is too much and over time (apparently 2 weeks) the continual rattle of water draining through the pipe (which isn't secured to anything) could slip slightly resulting in a leak.

Basically, the store is willing to either provide a new bulkhead and fittings or provide an entirely new tank. I'm leaning towards to later for peace of mind, but it will be a hassle. I had already done my aquascaping, and we all know what a pain it is to move tanks, water, substrate and rocks.

Any advice would be greatly appreciated. I've attached a couple of pictures of the new tank, pre-leak!

Best wishes,
Beignet


Attached files /attachments/sites/default/files/IMG_1018.jpg /attachments/sites/default/files/IMG_1020.jpg
 
If it were me, I would ask for a new tank. But at a minimum you will need to drain the tank and redo the bulkhead.

Can you post a picture of the plumbing?
 
Thanks for the helpful replies. Here are a couple of pics. The first shows the two return lines and the leaking bulkhead drain hole. The second is a view from the back of the tank.

On other thing I'm thinking about since it's likely that I will be requesting a new tank, is whether or not having hard plumbing everywhere is a mistake. The return lines are all hard pvc directly to the pump and the drain line (cut off in the picture) is also all hard plumbing down to the sump. I worry about pump vibration loosening the return lines/bulkheads and the water flow through the drain line shaking stuff loose too. Since I'm likely going to replumb a new tank myself, I'd like to get this right and would love to hear suggestions (especially if adding flexible hosing somewhere in the lines should be done).

Many thanks everyone,
Nann

Attached files /attachments/sites/default/files/photo_8.JPG /attachments/sites/default/files/photo_9.JPG
 
I've found you want the hole to be barely big enough to fit the bulkhead in. Sounds like a poor drilling job. Who did it? The store? Did it come that way? What storearewetalking about? I'd want a new tank.

As for the returns, why not have them go over one of the walls rather than drilling? Less bulkheads to deal with and easier to setup so there won't be any back siphoning issues.
 
An over sized hole sounds like a long term issue.
Suggest a new tank.

With fixed plumbing, things will flex and move a bit. If nothing else, just from thermal expansion.
What I do : Use LOTS of silicone. On both sides of the gasket, plus on the hole, plus the threads,
and even on the outside of the tank in the nut. And I only hand tighten, and not too hard.

+1 on returns over the top.
 
Thanks! A new tank has been requested! I don't want to share the name of the store as they really are trying to make this right and I think they are as surprised by this as is everyone else.

Regarding the return lines. The reason for the bulkheads is simply for aesthetics (and the LFS convinced me that bulkheads are 100% a-okay, clearly not true in all cases though). The tank I'm hoping for is rimless, clean, no visible wires, tubes, pipes etc. I've gone to great lengths to hide everything and keep everything tidy. Having over-the-side return lines will not be as pretty. That said, there isn't anything 'uglier' than a leaky tank :)

There is a one way valve on the return line just above the pump to deal with siphoning. But, again, with this being my first tank please advise if this is a bad idea. Also, if the water flow stops and drains down to the lowest spot (the drain line), all the extra water fits in the sump. So long as nothing is leaking or plugged, I think this is okay but correct me if I'm wrong here.

Nann
 
If drain is lower than returns then nothing to worry about. Don't trust the one way valve, sounds like its not important tho since the returns are up high enough
 
You might want to consider using schedule 80 for your bulkheads and true union ballvalves. If you are going for a clean look, why not just use schedule 80 throughout ?
 
I would use schedule 80, install some flex PVC on straight sections to provide a little wiggle, and seal the bulkhead with silicone inside and outside. I agree that over the side plumbing is safer. Eventually bulkheads leak, and this seems to be a problem more with side-mounted than bottom mounted, probably because of torque (downward pull) put on the bulkhead from the plumbing. So, if you can support the plumbing to reduce that torque it'd be best.

One way valves always fail, so don't trust them long-term. They get jammed up with gunk.

Glad you are getting a new tank! It's a pretty one.

Jonathon
 
You could also plumb the return through a bottom bulkhead with a standpipe to desired tank height. You just have to hide the pipe in the rockwork.
 
+1 on the schedule 80 fittings.
But I am not a huge fan of schedule 80 for pipes.

Minor : Due to thicker wall, the inside pipe diameter is smaller, restricting flow.

But there is a real problem with schedule 80! It is much stiffer and less flexible.
It is very easy for that to cause assembly issues, and put a lot more unexpected forces
on your bulkheads and other fittings.

Note that you can get grey and black schedule 40 online if color is a big issue.
Or better yet, paint it to match, and cover up glue marks.

I have heard good things about the new ultra-flex-pvc, but I have had
bad experience with the old standard flex-pvc.
 
I was thinking of doing a bulkhead for the return but now I'm not so sure anymore. However, I'm not really a fan of over the top returns. I plan on fabricating a screen top for my 40B to eliminate any chance for fish to jump out. Having an over the top return would open up that risk.

Is it really inevitable for vertical bulkheads to fail? I guess utilizing a glass-holes kit is out of the question too?
 
Inevitable? Over a hundred years? Probably! Lol
Just not that much cleaner to have a bulkhead for a return or a j tube or whatever they call it come over the wall. I get the clean look thing, but do you really want flow straight out of the back wall near surface height? If you stick lock line or anything else into the bulkhead to direct flow it gets a lot less clean in a hurry
 
Thanks for the tips. Since it looks like I'll be redoing the plumbing myself, rather than having the LFS do it the way they did before, I now have some flexibility to change things.

It's probably going to take me until the new year to tackle this project with work and holiday travel, so there might be a long pause in this thread. But, once I'm moving on this again, I'm sure I'll have questions and will post progress and start a build thread.

regarding hiding the plumbing. I actually have a black, custom ABS cover (in the shape of a trough), that will slip over all the back plumbing. The plan is to use it to hide the plumbing, but also I may glue some soft, sound absorbing media (maybe like egg crate) inside of it to absorb some of the drain sound. I've never tried this, but one of the things I like less than random tubes and wires everywhere is noise. We'll see.

Many thanks,
Beignet/Nann
 
Hi Mike,

I actually do like the flow near the surface. Having two returns, one on each side, gives subtle movement to the surface of the water and it makes the reef shimmer as if you were snorkeling.

The flow coming out of each return line is actually quite slow and is not what I'm relying on for tank flow. I have a vortech for that. I've read quite a bit about the flow rates through the tank and sump and my understanding is that a turnover rate of about 3X/hour is all you need. This is advantageous for extending contact time with the skimmer and any other sump filtration (so I've read).

The return lines are valved, so I can control the flow as appropriate, and I don't plan to add lockline to the return lines to direct flow since they aren't my primary circulation method.

I also don't plan to jam this tank to the brim with corals, but if this changes, I'll add another vortech.

This is my current thinking, but comments, as always are welcome- particularly on experiences and advice regarding tank turnover rates.

Beignet/Nann
 
Can someone point me towards the 'new' flex PVC and away from the old, bad stuff? Are the attachments made to plumbing parts with hose bibs and secured with stainless ring clamps?

The research begins.... Who am I kidding. I won't be able to wait until the New Year to fix this!!

Thanks,
nann
 
I have purchased from flexpvc.com and have been quite happy with the product. It glues into regular PVC fittings just like rigid pipe, though you have to be a bit more careful about priming before gluing and holding the join to get a really solid seal.
 
Beignet said:
The flow coming out of each return line is actually quite slow and is not what I'm relying on for tank flow. I have a vortech for that. I've read quite a bit about the flow rates through the tank and sump and my understanding is that a turnover rate of about 3X/hour is all you need. This is advantageous for extending contact time with the skimmer and any other sump filtration (so I've read).
Click to expand...

Interesting... I didn't know that a 3X/hour turnover rate was all that was needed. I presume that means if you have a 100g tank, you only need a pump that supplies 300 GPH with included head loss at minimum?
 
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