Weird yellow water

[Tanker]

Hi. Been a while. I have had great success with TFP. Thank you all!

I had a slight haze to my water and it just didn't seem right. Even though FC and CC were fine, and I could pass the coin test, I took it to SLAM level to try to determine if I had a chemistry or a filtering issue. I passed OCLT 2 nights in a row. So I'm good, right? I kept FC up again tonight for a 3rd OCLT.

However, I turned on the pool lights tonight and there was a slight yellow tinge in my water noticeable mostly in light reflection on opposite walls and around the white stairs. Is this chlorine? An optical illusion? Whatever, it is new to me.

Current results (tonight's except CYA not tested in over a week, pH not tested in 4 days)

FC 16.5
CC 0
pH 7.4
CYA 40
TA 70
CH 70

 

[jblizzle]

Do you have any reason to suspect iron in the water?

 

[Tanker]

Not really unless it's a very trace amount that would only show up if my pH is out of whack.

 

[ewkearns]

It is likely the color temperature of your lights. Probably nothing to be concerned about.....

 

[Tanker]

Color temperature? What's that?

Btw, this slight tinge is new. For sure it wasn't there the first night I slammed; it was there on the third night. I can't remember if I looked closely the second night.

 

[ewkearns]

https://en.wikipedia.org/wiki/Color_temperature

 

[Tanker]

I have to admit I didn't really understand that article.

 

[JamesW]

If it won't brush off, it's probably iron stains. Try ascorbic acid vitamin c on a spot to see if the yellow goes away.

 

[JVTrain]

ewkearns was just referring to the color temperature of lighting. I didn't know much about it until LED lights started coming out. Incandescent lighting has a color temperature of about 2700K. This is a slightly yellow hue. Some LEDs and the "daylight" CFL bulbs have a color temperature closer to 5000K which is a truer white light that can even look blue. Maybe your pool light is an incandescent and giving your water a yellow hue.

 

[Tanker]

Thanks, JamesW, but it's not on a pool surface; it definitely just shows in the reflection off the wall (and steps), not on the surfaces themselves.

And others, yup, I have regular old boring lights.

It's just so strange that I never saw this phenomenon before. Do you know if the visibility of the color temperature thingy is affected by water chemistry? I (luckily -knock on wood) only go to shock level at open/close and certainly not for 3 days in a row and I am wondering if my unusual water chemistry is to blame.

 

[Tanker]

Just an update. The yellow color went away after I let my FC come down. I don't know how to explain it, but I'm glad it's gone.

I still have the same haze so I am figuring it's filtration. It is much more noticeable at night when the lights are on. Some larger floaties, but mostly finer stuff. I add DE to my sand filter after a backwash. I brush often enough.... Any ideas besides deep cleaning my filter? I am scared to do that because I am not mechanically inclined and worried that I may damage my spider gasket.