Calcium Deposits in Light Niche

[mdthomas176]

I did a mustard algae shock last week. I pulled the light from the niche for the first time, and it looked like there was a lot of calcium deposit in the bottom of the niche. Basically it was taking up the whole bottom of the niche, maybe an inch deep. This is my second season with the pool, and I never looked behind the light before. I wanted to see if anyone had any thoughts on that. Unfortunately I didn't take a picture while the light was removed.

I have a plaster pool. When we moved in, the chemistry was a mess, so I wouldn't be surprised if there was long standing calcium hardness issues over the years. Or maybe the deposits could have settled there when the pool was replastered (no clue when that happened thought)? I now have the chemistry in line with the TFP guidelines. Last year CH was around 350. I have it at 400 this year.

I just put the light back in and left it alone. I don't have any other issues with the light or niche, so I figured this was a leave well enough alone situation. I wanted to reach out and see if anyone has any insights for me.

 

[duraleigh]

Is it granular (removable) or stuck hard to the niche?

 

[mdthomas176]

It was stuck hard to the niche. I brushed it to make sure I got at any algae that was lurking in there, and it stayed in place.

 

[duraleigh]

That's quite unusual. Can you post current test results?

 

[wireform]

No poolin signature, so is this plaster or vinyl.

 

[duraleigh]

From his first post....."I have a plaster pool"

 

[mdthomas176]

here are test results from tonight. I also hopped in and took a photo of the niche as best I could.

PH: 7.5
FC: 7.5
CC: 0
TA: 60
CH: 325
CYA: 30

The more I think about it, maybe it’s just some leftover mess from the replaster job.

 

[wireform]

That was my initial thought too when I had asked about what kind of pool it was. If it's rock hard I'd guess it's plaster from sloppy work.

 

[mdthomas176]

Yeah, that seems plausible.

From videos I’d seen when looking up how to remove the light, I was not expecting such a rocky mess back there.

 

[duraleigh]

If it's rock hard I'd guess it's plaster from sloppy work.

I agree with wireform. Harmless enough but sloppy work.

Your Test results look very, very good.

 

[mdthomas176]

I agree with wireform. Harmless enough but sloppy work.

Your Test results look very, very good.

Hopefully the sloppy work doesn’t manifest in more serious ways down the road…

Appreciate the test results feedback. It took me a while to square things away last summer, and now that things are settled I feel like I can enjoy the pool more.

The mustard algae threw me for a loop. Hopefully it stays at bay. I only realized what it was a few weeks back. Algae on the shady walls of the pool. FC was always sat, and I was passing the overnight loss test. I do wonder if I’ll just forever have that battle though. I have a pond close by that will probably always be an algae engine for my pool.

 

[duraleigh]

Mustard Algae is easy to eradicate but you must be diligent especially after the SLAM. Brushing the walls and pool floor probably twice weekly will be a big helphelp. Of course, keeping adequate FC in your pool is the overall key to success.