ABS and UV don't mix.

[DerekC]

Just wanted to share this.
I bought an emperior aquatic UV 25W used 2-3 years back and after a few months of use, it started leaking. The wall got thin and ruptured. I replace the body with home depot ABS 2" pipe and today it ruptured again. You can see how the wall get thinned that I can pressed down with my thumb:

So, this time I replaced it with PVC (scheduled 40 - too bad I could not find schedule 80 locally quickly) and added a union (so that I can rotate the inlet outlet position):

I don't know if the body was replaced with ABS when I bought it used. Emperior Aquatic (now Pentair) uses some material that is UV rated?
PVC is not UV rated either according to my research (and I can't paint the inside of the it) but it should be a lot slower.
Will see how long this would last.

 

[S-t-r-e-t-c-h]

Some manufacturers produce UV stable CPVC. The PVC is going to deteriorate eventually too (as you noted).

 

[NMdesertReefer]

I wonder if electrical PVC would work its UV rated.

 

[garbled]

I live in Arizona. (wait, this is relevant!)

Sometimes I leave (white SCH40) PVC pipes in the back yard sitting outside. The UV gets to them.. They turn brown, degrade, and fall apart.

 

[scriptmonkey]

I live in Arizona. (wait, this is relevant!)

Sometimes I leave (white SCH40) PVC pipes in the back yard sitting outside. The UV gets to them.. They turn brown, degrade, and fall apart.

But there is not any ozone protection in AZ, just straight solar death ray!

 

[Bigtrout]

I wonder if electrical PVC would work its UV rated.

Electrical PVC is UV rated and you can get it in schedule 40 and 80...its the same dimensions as pvc water pipes, and the same glues work.

 

[Eagle_Steve]

Electrical PVC is UV rated and you can get it in schedule 40 and 80...its the same dimensions as pvc water pipes, and the same glues work.

I second this. My koi pond is all electrical pvc for the plumbing and my UV is inside the pipes as well. So far 10 years and all that gets replaced is the bulbs.

 

[Bigtrout]

I dont know if id use it in a high pressure situation, but for the low pressures in aquarium situations its fine.

 

[Hermie]

Based on my research, PVC will be fine, what happens is less than 1mm of the surface will become affected, but it won't penetrate past that. It's why ABS is for underground/drainage situations and PVC can be exposed outdoors (which is what Conduit can be made from).

 

[Bigtrout]

Based on my research, PVC will be fine, what happens is less than 1mm of the surface will become affected, but it won't penetrate past that. It's why ABS is for underground/drainage situations and PVC can be exposed outdoors (which is what Conduit can be made from).

Yes but white plumbing pvc is NOT uv rated, but electrical conduit is rated for use in direct sunlight.

 

[Hermie]

Yes but white plumbing pvc is NOT uv rated, but electrical conduit is rated for use in direct sunlight.

thanks, I got kind of lucky that a conduit box was the perfect fit for my DIY UV. I would have used white pvc if it "fit" better. That said, part of it is made out of white PVC (spigot end cap that the light attaches to).

 

[GK3]

I wonder if electrical PVC would work its UV rated.

You’d have to check and see what else is put into it besides just PVC. If it’s PVC that is UV resistant, it must have a coating or something on it. The two questions are 1) is that coating everywhere or just on the outside 2) since this isn’t made to go in water, will salt water eventually deteriorate it or worse, will it leach a chemicals into your tank.

 

[GK3]

Based on my research, PVC will be fine, what happens is less than 1mm of the surface will become affected, but it won't penetrate past that. It's why ABS is for underground/drainage situations and PVC can be exposed outdoors (which is what Conduit can be made from).

PVC by itself is not UV rated. PVC is a polymer and UV will breakdown the bonds in polymers. There has to be an additive or coating other than PVC to get this rating.

 

[Hermie]

PVC by itself is not UV rated. PVC is a polymer and UV will breakdown the bonds in polymers. There has to be an additive or coating other than PVC to get this rating.

yeah I should have defined what "fine" means because it's inherently subjective, that said, the question now is, would the polymer degradation be enough to harm a reef tank?

 

[Hermie]

I painted the inside of a conduit box with Krylon fusion black because I was worried that UV would damage the PVC, but it turns out that the UV did major damage to the paint instead. It became powdery and was coming off, I am sure it affected the fish in my tank. So I definitely don't recommend Krylon Fusion to "protect" against UV used in a sterilizer... I ended up just replacing the conduit box and using a "Fresh" one without paint.

 

[DerekC]

I should have used this:
2 in. x 10 ft. PVC Schedule 40 Conduit
Since it is for outdoor so it should be somewhat UV rated (with additive, pigmented, or coated). It is cheap. I can get it locally. Too bad it is not schedule 80.