UV sterilizer plumbing

[DmitryB]

I'm also have a little trouble trying to picture what you're trying to do, and I don't want to guess the wrong configuration. Would you be able to draw it out a little bit?

In general, yes it sounds like a reducer bushing is what you're looking for:

These would slide into a PVC fitting like a pipe would. You can get various configurations of sizes, with options for slip or thread for either connection. There are reducer couplings too (which go over PVC pipe) but it sounds like a bushing is better for you, if I'm picturing things correctly.

The way you'd switch from PVC to vinyl tubing is with a barb adapter:

These are also offered with various configurations of thread and barb size, and you can get ones with male and female threads. So if I were going from, say, a 1.5" PVC fitting to 3/4" vinyl tube, I'd look for a 1.5" x 3/4" FNPT reducer bushing (i.e. with the 3/4" hole being threaded). The other side can be slip or thread depending on what you're connecting to. Then I'd just need a 3/4" MNPT x 3/4" barb adapter, which is an easy size to find. The barb adapter should be plastic (the brass ones will rust and they can kill invertebrates).

Use teflon tape on the threaded connections, but if you haven't used if before be sure not to use too much. The added pressure can split fittings in some cases.

Also, you'll need a hose clamp to make sure the hose stays on the barb. Stainless steel (if it will be dry) or plastic (if it will get wet) are both options. I feel like the metal ones do a better job, but even stainless steel will eventually rust in seawater, so sometimes I go for plastic. I always go for plastic if it will be submerged.

I'm not explaining it well because I don't know plumbing so I'm more like "Can this doohickey go on that doohickey and work?"

I'm working on another diagram that will hopefully be clearer than I am! All the photos above are great, exactly what I need. One thing I hope I can make is True Union Ball Valve that is also a reducer, so I can skip an extra step of plumbing.

And I'm STILL trying to determine where the actual UV unit will go. There is just so little space in the stand that it's frustrating. I've figured out a way to hang it above, but it's still so tight with the skimmer sticking out of the sump. It will absolutely be in the way of doing anything inside the stand. So... I was trying to avoid placing it behind the stand - there is just enough room to fit a UV there, between the stand and the wall. But it will clear a lot of space in the stand, so I think that's where it will go. Now I just need to decide if it will stand on the floor back there or if I can elevate it to be at the top-of-sump level, so there is a bit less plumbing. I'd need to make some sort of platform for it to sit on...

Thank you guys! A new diagram is coming soon! (By 2028 I should have it all figured out.) I'd love to finally connect it. I put a UV on my 40 gallon (drop in UV for an AIO) and the water cleared up so beautifully that I'm looking at this 170 and going "Grrrr."