PVC/Plumbing help!

[RyanH]

I have a problem that I'm going to have to address relatively quickly. I bought a used 90g tank that was pre-drilled. The plumbing and fixtures were all attached already. I filled the tank with water and let it run and there were no leaks. I put in the DSB and LR, and after a couple of days, I see a small leak forming. Here are the details.

The bottom of the tank is drilled in 2 places toward the back of the tank. There are 1" bulkheads installed. Under each bulkhead is a PVC ball valve (screwed in with plumbers tape) and below that is a barbed slip nipple for 1" flex tubing. I think the guy who owned it before used this set up to do water changes.

Anyway, there is water forming around the bulkhead-ball valve joint. I cant take this assembly off without completely emptying the tank.

Is there any way to seal this joint without tanking it apart? I was thinking about putting a bunch of PVC cement around the joint. I think I the PVC cement actually melts and fuses the plastic, so this might be a solution? Any help would be greatly appreciated. Thanks.

Ryan

 

[jdeets]

I'd recommend plugging the bulkhead from the inside. Then you could remove the ball valve and put more plumbers' tape on it.

Also, is it possible the leak is actually coming from around the bulkhead and dripping down to look like it's coming from the joint between the bulkhead and valve? If the bulkhead is installed too tightly, it will leak.

Anyway, if you're sure it's the ball valve, I'd just plug the bulkhead from the inside so you can remove the ball valve and re-seal it.

 

[fnj]

Ryan, are you sure that the leak is at the ball valve/bulkhead connection. I've always had problems with the bulkhead themselves leaking a little after the plumbing is finished. The water could be dripping from the bulkhead and pooling in the connection of the ball valve. The bulkheads loosen up pretty easily when messing with the pipes that are connected to them. Try tightening the bulkhead a little more. I've also heard of people using silicon on their bulkheads as well, I've never had to do that but you never know.

If it is the ball valve/bulkhead connection you should be able to tighten that down a little more as well.

Frank

 

[RyanH]

Thanks for the input. I'll double check the actual bulkhead connection.

Regarding plugging the bulkhead itself, how would I do that? I suspect I would have to take the ball valve off to do it, which would require me to drain the tank. It sounds like something I would like to try.

Thanks.

 

[fnj]

The bulkheads are threaded all the way through on the inside. To plug it you can attach a male theaded connector to a section of pipe that is higher than your water level. Then screm that into the side of the bulkhead that is inside of your tank so that the end of the pipe is above the water line. Then you can unscrew the ball valve from the piping and you will not have any water in the plumbing.

Or if you can reach your hand down into the tank where the opening of the bulkhead is you can just screw a cap into the bulkhead opening.

HTH,
Frank

 

[jdeets]

I take it there are no overflow boxes? If you have overflow boxes, turn off the pump and let the water drain to the sump. Then siphon out all the water from your overflow box. I had to do that with my 180 to fix some leaks that formed during setup. In my case, I actually had to remove the bulkheads.

If there aren't overflow boxes, then at any rate the inside of the bulkhead should be threaded. Get a PVC bushing with that thread size, glue a piece of pipe into the bushing and finish it off with a PVC cap. Screw that into the bulkhead and viola, it's plugged. If the bulkhead has a standpipe coming up from it and you're just using a Durso or Stockman overflow pipe with no overflow box, then just turn off the pump and once the water drains into the sump, there should be no more water going through the bulkhead. In that case, you might want to siphon a little more water out of the tank to keep it from going into the overflow while you're working. If your bulkheads are on the back of the tank up high, same then use the same procedure as you would for a Stockman or Durso standpipe setup. Whichever is applicalbe of these methods should work, as long as your plan is not to take out the bulkhead but to work on the joint between the bulkhead and the ball valve.

Also, the main thing to remember when working with bulkheads is not to overtighten. An overtightened bulkhead will leak like a sieve. Finger tight is fine for bulkheads.

 

[davelin315]

I agree with the above posts, plug it from the inside. The bulkhead will either be threaded or unthreaded. If threaded, just screw a cap into it. If unthreaded, just take a piece of pipe longer than your water level, and push it in (make sure to clear the area out around it so that your sand does not get in there on either scenario because the water will continue to leak otherwise through an imperfect seal). As far as pouring cement there, don't do it. PVC cement will dissolve the pvc, but it will not patch a hole for you unless you are very lucky and can get it inside. The best way to avoid a leak on a fresh weld is to twist the pipes together before the initial set sets in. As far as redoing the set up, you may have a problem because it sounds like the leak set in after the added weight of a DSB and LR. There might be too much weight on the bottom of the glass and it might be causing the glass to flex ever so slightly, causing an imperfect seal. Just a guess though.

 

[humu]

man leacks are always scary. one time I came home and found the carpet soaked, but afer I cleaned it up there was never another leak. wierd yeah!?
man I always trip when I see you name "ryan H"
my name is ryan H too!

 

[RyanH]

I hadn't thought of plugging it from the inside, but mainly because i have a DSB 5" deep and moving it away from the bulkhead to screw in a plug is going to be tough.

There is an corner overflow box, but these two holes are drilled into the tank itself. Basically, the guy who owned the tank before me put a 1" bulkhead in each back corner of the tank. Below each is a ball valve (where i think the leak is occurring) and above each is about a 6" piece of 1" PVC, then a 90 degree elbow, then these two elbows are connected by a horizontal pipe that has multiple holes drilled in it. The horizontal piece has a "tee" with a riser almost up to the water surface.

The stragegy is to hook a powerhead up to the top of the riser to move water from the top of the tank and push it out of the spraybar at the bottom of the tank behind the live rock. A secondary or alternative use is to facilitate water changes by turning off the powerhead and opening the ball valves. The water would be removed from just above the sandbed.

I like the set up, but the leaky ball valves are definitely a problem. I would like to keep this system functioning, but I can't have this leak, regardless of how slow it it.

I may try to figure out a way to put a valve either right before or after the 90 degree elbow. Then only problem with this is the bulkiness. Any thoughts on this?

Thanks again.

Ryan

 

[jdeets]

Ryan, at this point, I'd wrap the horizontal pipe (the ones with the holes in it) with something to restrict water flow into the pipe. I'm not sure what I'd use--whatever you use, it would need to be inert so as not to put anyting in your water. Perhaps you could take some latex material (like they use to make surgical gloves), wrap that pipe up really tight with it and secure it in place somehow to stop any water from flowing through those holes. Then plug the top of the pipe also. Then you can remove the ball valve that's leaking and re-wrap the threads with teflon tape to stop the leak. That's what I would do, anyway. You'll just need to get creative on what to wrap it with and how to secure it. I think you can get latex strips and you could wrap with that and secure by tying the loose end around the vertical pipe. I'm not sure where you can get the latex stripping, but I know you can get it somewhere. Perhaps someone else can give you a hint on where it can be found.

I wouldn't put the valves inside--then you'd have to reach way down into the tank to turn them. I'd leave the whole assembly in--sounds like a great way to do water changes!

Good luck!

 

[RyanH]

James,

I think you are right. I am going to try to salvage the system. What I might try first is to take th horizontal tube out and plug the elbows with a 1" PVC plug on each side, then change the ball valves.

If i can't find a decent way to make that work, i'll try to figure out a way to plug the holes.

I really appreciate the ideas and input. I'll let you know what I come up with and how it works out.

Thanks

 

[davelin315]

See if the pvc is cemented in place. When I do something in tank, I seldom cement the pieces together, as you don't need that tight a seal inside the tank, you can just push the pieces together and that will pretty much do the job, with minimal leaking. You will be able to see if it's glued together usually by looking to see if there is a small "ring" of clear solvent around the seam, kind of like a bead of water going around a seam on a leak (you know what that looks like

). If it's not glued, then just pull the assembly off and put some lifts on the tubes using couplings. Otherwise, you can always just cut the elbows off as close to the seam as possible and rebuild the contraption without cement (or you can cement it if you're concerned, although with the holes in there, you won't need to cement it as it's not watertight). PVC is very easy to work with, but you may ruin your cutters when you dip them in the tank to cut the pvc. I would wash it with a good dish soap, rinse it thoroughly, dry it, and then cut the lifts, then wash, rinse, and oil them (that is, if you want to cut them).