Black stain removed with puck (and mothballs?)

[Deb04]

The inside of my skimmer has black marks above the water line. I tried scrubbing it with a dish brush I bought for tough to reach spots in the pool and they didn't budge. I'd read on here that pucks can remove some stains, so I tried it. I have a small bucket of pucks I use at the beginning of the season when my CYA is near zero and the water is too cold for the SWG.

The puck removed the stain. Now two questions:

1. What does it mean that the puck removed the stain? Does it mean it's algae or just that it needed to be bleached out?

2. The pucks are stored in the shed. We put some mothballs in the shed to keep the mice away who had chewed 3 holes in our winter cover last summer. The puck started to stink of mothballs once it got wet. It continued to smell (of both chlorine and mothballs, an awful combo) the entire time I used it. Do you think there's a problem? Did I just put the equivalent of a mothball in my pool and, if so, is it an issue?

Thanks.

 

[JoyfulNoise]

Either move the chlorine tablets or the mothballs, they should not be in the same shed. Mothballs contain naphthalene which is a solid that sublimates naphthalene vapors at room temperatures. Those vapors can easily condense back into solid form when it cools and it is likely they can get to the chlorine tablets. Poly-chlorinated naphthalenes (there's about 75 different PCN compounds possible) can form in a variety of ways and are hazardous compounds that you should avoid exposure to. So simply move one of them somewhere else.

The dark stains on the skimmer are just organic compounds. Nothing to worry about. I use a Mr. Clean Magic Eraser sponge to clean the discolorations off. Works like charm every time.

 

[Deb04]

Thanks.

Now I'm wondering what to do with the remaining pucks that now smell like mothball, so I assume hazardous stuff may have already formed. Safe to just use them? I need to raise my CYA anyway.