Mr. Saltwater Tank

Terrible Advice Tuesdays (T.A.Tues): The Easiest Way To Plumb Your Saltwater Tank


Terrible Advice Tuesdays: There is no need to glue PVC pipe and fittings. Just push the pieces together enough for them not to leak.

The rest of the story: On one level, this fact is true. You could probably cram two pieces of PVC together enough that they won’t leak. Getting to that point will likely require more effort than you can exert with your hands, especially considering the tight places underneath your tank.

Since there would be no glue holding the pieces together, if you bumped or rotated the pieces, then they could start leaking again. Sounds like fun huh?

Glue your PVC pieces. It takes very little time and when done correctly, the connections won’t leak even if you bump your plumbing.

Note: Some people have reported using silicone in place of PVC glue so that they can easily disassemble their plumbing. While I prefer PVC glue for a cleaner, more permanent solution, I can see how using silicone could work.

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Comments for this article (23)

  • Tony says:

    silicone will not work, it will release it self after a while just like it does on acrylic if you use acrylic in a glass tank sump for baffles. It will eventually let loose from the oils they are made from.

  • Jim says:

    glue them together every time never rely on just pushing them together
    if you ever have to take them apart it is easy just grab a hair dryer put it on high and blow on the joined parts, just ask a plumber they do it all the time it is cheaper than cutting and replacing and the cost of new connections.
    Yes I have done it before on my tank and when we installed our new kitchen.
    make sure you use the right glue
    Type ‘N’ Blue for non-pressure applications
    Type ‘P’ Green for pressure applications including potable water
    Type ‘G’ Clear gap filling for parallel or low interference pressure and non pressure joints

  • Whitey says:

    What is the “right kind of glue” for attaching a drain hose to a sump? I’m guessing it would be ‘G’. Are all three removable with the hair dryer method?
    Thanks for any help!

  • Whitey…just get any PVC glue in the plumbing section of a hardware store. I get the “medium” grade

  • Matt says:

    The cost of a little time and glue to save from a potential tank wiping disaster… I’d rather the high as a kit headache any day!

  • Bob says:

    One other thing that will help if any mods or changes need to be made later is use a lot of unions. Unions make alignment so much easier.

  • Carl says:

    Also, since the glue melts the pipe on the joint, it will fully fit into the joint. This let’s you get results extremely close to what you measure and plan for. You can not do that with unglued joints and get unpredictable results. I consider it easier to glue. And if you use unions it is easy to fix mistakes and to modify in the future.

    What I don’t do is use primer. These are low pressure joints and is not needed. I just find the primer to thin and messy it seems to get everywhere you don’t want it to.

  • Ed Cilumbrello says:

    With a smaller pump it may not be necessary. With higher volume or pressure pumps, prime and glue the pressure side with medium potable water PVC glue. I never glue the suction side.

  • T George says:

    Always primer/cleaner both sides. (same stuff one has die for building inspections) this loosens the bonds of the PVC. Then glue on both sides. Then one extra glue pass to both sides. Push together hold for 30 sec. 15 min handling strength. Leak test after two hours.

    Your not really glueing when properly done your welding the pipes together. This is why the primer/cleaner is so important. Loosing the material to bond together. Similar as puting together acrylic tank. 🙂

  • John Collinsgrove says:

    I glue and prime everything with exception of “in a reef ready tank” the stand pipe on the drain and the 90 on top of the return line that goes to line loc.

  • Glenn Campbell says:

    I’m about to set up a new tank and I’m thinking about using the fittings from hydrorain.com, these fittings don’t require glue and i saw a demonstration where they put over 900 psi of pressure before it blew the fitting off, and you can disassemble it at any time.

  • EaVee says:

    I’ve used thread tape to seal the PVC joints on fitting that i like to take apart regularly. Glue irritates me when i want change/mod my system… that being said i have never tried using heat to separate glued fittings maybe i can change my ways back to gluing…

  • Rob in New Jersey says:

    I always primer & glue the pvc together. If you need to separate the pipes, use a union. Unions can get costly but it make swapping out parts, taking the components down for cleaning and reconfiguring your plumbing easy. I also use threaded couplings on the other end of the pipe. I can swap out a return pump in a minute and will not have any leaks. You need to deburr the pvc pipe, properly prime, and correctly glue the pipes to prevent leaks. There is a pvc glue available at the box stores for damp/wet pvc. Using heat will work if you are using Schedule 80 pipes however it is very difficult to separate Schedule 40(white) pipes.

  • Beetle Bailey says:

    Wow , hot topic, well I’ve had pushed together joints come apart and leak,wasn’t serious but still a pain in the butt & could have been a real disaster, with a little advanced planning & putting unions that you can unscrew the pipes should you need to in the right positions, glueing your pipes is the GO

  • Nicolas says:

    My question has always been: Once you’ve glued it. Then what? How do you unglue your fittings?

    I’ve actually always used plumbers tape and silicon. And yes, silicon doesn’t hold forever.

  • Nicolas says:

    How exactly do you heat the piping to unglue it?

  • Rob in New Jersey says:

    You can use a heat gun but be careful not to burn the pipe. Once it is apart it will be very difficult to reglue and get a water-tight seal.

  • Pierre Bouic says:

    While some of you will not agree with this, I only glue what is needed to be. What I mean is the pipes that are for pumps or anywhere that it is necessary to have solid plumbing, yes by all means glue it, but lines that may be connected to things that are needing maintenance such as MY mud box that I grow macro algae in. This is in a tight spot under my tank with very little room to harvest the excess macro or replace the VHO light tube on to of it, the bud box needs to be slid out, for access to slide the mud-fuge out I need the return drain to be pulled apart so I use thread tape on the PVC pipe. This is one example of an area of plumbing that is pulled apart for access so the use of thread tape is how to stop the PVC from leaking. This won’t work for all but as I was a plumber & my set up is not all concealed under a tank stand, this is what works for me. My set-up has 3 glass tanks under it & not all fit under the tank. Soon I’m going to redo the filtration & refuge, to make it larger, so I will be able to pull some of it apart. This is possible because I have a tank room. Different strokes ETC. I do agree with Mark on this one but what I do is specialised so my skills let me do what is needed.

  • chris says:

    silicone wont last long, takes longer to cure especially if u bump it before it cures properly. use pvc glue. it actually etches itself into the fittings and creates a seal that will never leak and is reasonable ridged.

  • Igor says:

    One piece I made from PVC and did not bother to glue is durso pipe in my overflow box. It has nowhere to leak but into my sump anyway. And in fact it is convenient because I can take it out and apart and clean once in a while.

  • Lyle says:

    Hey! all of this to glue or not to glue is crazy why not play it safe and glue all joints but use unions where needed! They unscrew so no need for hair dryers and time consuming bad ideas! U can get unions from all of the home supply stores as well as Bulk Reef Supply etc. Why risk a damage causing leak that insurance won’t cover and also the chance of your fish and corals dieing! Just a thought!

  • Ed says:

    Here is a question for you Mark.. If your house is plumbed with copper pipe and you install a RO/DI unit for your fish needs, will the RO/DI unit filter the copper out of your water?

  • Lyle says:

    I myself would say yes but that is a good question! I have well water but there is copper pipes in the house! It was built in 1783 but all plumbing was updated to copper. I use NovAqua water conditioner and have never had any issues with copper killing my inverts or corals! Anemones are the canary in the mine test subject because when they come into contact with any levels of copper they look like they are going nuts in a sort of way! tentacles doing all kind of crazy stuff. Even though I am hooking up an RO/DI unit I still think I might still use the water conditioner! have used it for years and always add it when I am acclimating new fish in buckets with a drip system! Helps at least with there slime coat and any damage they might have sustained from being caught and then transferred home! When I worked at a pet store I would always put a shot in the bag for my customers just as a precautionary/insurance policy! Who knows? There are copper test kits on the market! Mark back too you! What is your professional opinion or fact! Lyle Also HAPPY New Year just in case I am not answering questions or adding to the discussion! Also just picked up supplies for my new diy custom filter and frag system I am building!! Think I will be up all night working on it! LOL!

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