What to do with my pool light niche that keeps rusting... including on the cord!

[iwant2save26]

First, a little history: This pool was resurfaced in September 2017. Prior to that we had no rust issues with our pool light. They put in a new pool light because the 30 year old bulb in the old one had died.

In July 2018, I noticed a small rust stain underneath the pool light. I called a pool repair man (not the company that did the resurface, because they did a lousy job on certain parts (pool coping) and I didn't like them.). He came, removed the light fixture, found what he thought was once a screw that the company left in the niche. He scrubbed the rusted part with some sort of stone and then used a pool pole to pour a good amount of muriatic acid on it. When he finished, I could not see any rust.

Fast forward to today. I decided to check the pool light to make sure there are no more issues. I unscrew the light and find even more rust in the niche! The part that he cleaned is rusted and further back (which he likely couldn't see because he didn't get in the pool... and neither did I.) there was something else (another screw?) that had rusted.

Here are my questions:

1. Can the niche be replaced? From what I'm reading online, I don't think it can.

2. There's a big rust spot on the cord for the light. (pictured) This seems a bit hazardous. Couldn't it allow electrical current in the water if it rusted deep enough?

3. What's your best suggestion about how to handle this? Part of me wants to have someone just fill it in, but I'm skeptical that there wouldn't be an obvious finish difference between the pebblesheen applied last year and a patch. I don't care about having a pool light as we never swim at night...

I am not thinking of doing any of these repairs myself unless they are super easy. I get nervous about electrical things. I just want to know what the best direction might be so I can be prepared when I get someone to come out to see it.

Pictures can be found on my dropbox at: Dropbox - Pool Light Damage Collage.pdf.

I tried attaching them, but it kept telling me the pictures were too big. Even when I put it into a document collage, they were still too big. Not sure how else to show you all the pictures....

 

[ajw22]

What is your water chemistry? What is your CSI? How often you check your PH?

 

[iwant2save26]

Sorry for the delay! I was out of town this weekend. Current readings are:

FC: 5.0
pH: 7.6
TA: 80
CH: 375
CYA: 75
CSI from poolmath: -0.4.

I check my PH daily. Since the pool was resurfaced last September, I have to add acid every 2-3 days to keep the ph between 7.4-7.6.

 

[iwant2save26]

I took the light out of the niche today and used a scrub pad to remove the rust from the light and the screw. Came off pretty well. I was also able to remove some small rust spots in the niche with the same scrub pad, but not the biggest rust spots, just the little spots on the sides. Also, noticed my cord looks melted in some places. I currently have power turned off at the breaker, but wondering if I could ever use it safely again?

Any recommendations for pool light repair companies in SW florida? Sarasota/Bradenton area?

 

[ajw22]

Areas that rusted will rust again. The pool light probably can't be repaired. It should be pulled out and a different light installed.

 

[iwant2save26]

I am all for having someone replace the light, especially with the cord looking as it does... but with the niche having rust/corrosion in it, won't the new light just rust again? The current light is only one year old. The light before it never showed any rust outside and worked for 25 years....

 

[ajw22]

Things don’t seem to be made the way they used to.

Maybe a different model light will be more rust resistant.

 

[JohnT]

My bet is that you have galvanic corrosion from a bad cord. Current is flowing from the cord through the water to the niche causing the rust.

 

[sktn77a]

If you can get the old niche out, you can replace it with SS or plastic/fiberglass. The niche that was put in must have been awful cheap to corrode that quickly. Running the new light cable up through the conduit will likely be the most challenging part.

 

[kadavis]

It appears they plastered in a light ring that would accommodate the newer light. It also appears that the grounding lug in the original niche was never encapsulated. It may may be something going on between the ring which is probably not grounded or bonded and the grounding wire