I would like some input on how people hooked up their overflow systems.  I have a 120 gallon overflow tank (pre-drilled).  Originally, I hard plumped it but in the move I had to break out the saw and cut the pvc in order to drain/move.  The main suggestion I am looking for is how to hookup the pre-drilled area and using a bulkhead.  I was at Mountain shadow and saw threaded (both sides) bulkheads and was wondering if anyone has used them.  My goal is to be able to change out any part without having to saw it out.  Threaded connects make me paranoid with the potential for leaking.

John

John, I used a bulkhead fitting that allowed my 3/4 pipe to slip fit into the bulkhead fitting itself.  The outside is threaded and I simply tightened it up.  The pvc is glued at the slip fit.  All I have to do is break the seal of aquarium sealer that I put around the bulkhead fitting inside the overflow box and I can then slip the entire 4' piece out the top of the overflow.  There are many types of bulkhead fittings available with just about any combination threaded inside and out or threaded one-side or the other with slip on the opposite.  I have a catalog at home for a business called Aquatic-eco systems, that I could bring to work one day.  We could meet for lunch or just arrange a meeting.  You are also welcome to come and see how I plumbed my setup.  Good Luck!

P.S. How did the move go?  Are you somewhat settled in?

The move went great...thanks.  Settling in is taking awhile but it sure is worth it going home every night...even without the show tank set up. 

Unfortunately, I place a slip joint elbow just below the drilled hole, so I couldn't just pull it through.  I saw the double sided bulkhead at Mountain Shadow and was thinking about skipping the slip joints so I would be able to simply unscrew to dismantle.  My concern would be on the inlet side where the pressure is high.

John

Sounds good!  I outsmarted myself!  I wanted the plumping as high as I could get it to keep it out of the way...in order to get the bulkhead out, I had to cut the bulkhead itself.  So I have ruined all of them and now have to shell out $50 for bulkheads alone, D'oh.

Your idea sounds like it would work which I have thought about doing if I hard plump it again (leaving space for cutting out). 

John

I'm sorry you had trouble. I'm not exactly sure how you did this. Was the threaded end of the bulkhead pointing down with the nut on the underside of the tank but no extra pipe to re-use when you cut off the elbow? If you had not already cut it, I could tell you how to cut the fitting off and save the pipe inside. If I am understanding your setup, this would have saved you the purchase of new bulkheads.

Glued fittings are really best. Threaded joints in saltwater will always have the potential to leak and cause salt creep unless there is a rubber seal involved.

Hard PVC piping is not so difficult to work with after installation as you may think. Just cut the pipe and rejoin it with a "coupler" or put it together with Unions or compression fittings. MSM sells the flexible PVC called "Sterilite". This makes hard piping and glued joints a little less rigid.

Mark,

Right, there wasn't any pvc left to couple.  Are you going to be at MSM tomorrow?  What time?  I'll stop by and you could show me the flexible pvc.  I was also thinking about getting away from the pvc and going with tubing...sounds like what you're talking about is a cross between the two?

John

I'm off till Saturday 11-5, but if you call I could meet you there tomorrow afternoon. Also, Dave, Cory or anyone there can show you the Sterilite and give their opinions.

Careful though, it's not even close to being as cheap as ordinary PVC sprinkler pipe.

IMO Poly-vinyl tubing is good for a few years, as long as it's clamped good. But it shrinks within a year, increasing resistance and reducing flow.

Bruce and Jon did a great job last meeting telling us about water movement. We observed a demonstration showing that, in applications regarding an external pump on medium to large tanks, 1" pipe is the most effective. In addition, we learned that slow bends are better than hard 90 degree elbows.

Mark,

Unfortunately, I had to miss that meeting.  Sounds like it was pretty informative.  I also have a question about the overflow pvc being 1 1/4 instead of 1" (which it was previously).  Would this decrease in resistance increase my (over)flow volume?  Likewise, would increasing from 3/4 to 1" in flow to the tank increase flow?  Keep in mind that I have potential bottlenecks in smaller diameter areas like the bulkhead and I am running my inflow through 2 x 3/4 inch sea swirls.

Thank you all for the input so far.  Sounds like I will stick to pvc slip fits since I haven't read any testimonials swearing by threaded connects or the sterilite.

John

Some day I've got to hook up that skimmer!

Not you Mark, tell me it isn't so!

John