Staining/Lightening on Fiberglass Pool

[ny2nc]

Hi folks!

Not sure if I am posting this in the right place, but hopefully one of you lovely folks will redirect my post if needed.

We have two sheer descent waterfalls coming from a rock wall into our fiberglass pool. We almost ALWAYS run the waterfalls, so I never really noticed this until this week. When the waterfalls are off the rock underneath the waterfall and the fiberglass there is lightened/white. I haven't gotten in the pool yet this year (I will any day now though!) so I don't have in depth information about the white marks. I don't know if it is some sort of build up or if it is bleached. If it is somehow bleached I might cry.

Any thoughts?

 

[Texas Splash]

Should not be a bleach issue, but could be scale that's accumulated in that area simply from being isolated. Oxidation is possible, however being tucked under the falls would seem to help keep the sun from being so intense. Once you get a chance to look at it closer let us know.

 

[ny2nc]

I'm hoping to get in there later today to investigate. In the meantime, here is a photo of what I am talking about in case that helps!

 

[Texas Splash]

Is it those streaks you are talking about? Yeah, I suspect that's residual calcium of sorts. No different than if the water constantly ran down the face of a stone ledge or something. Regardless, not bad. You could try a variety of things there. IN a small test area, I would start with something like a Magic Eraser. If it's embedded more into the gelcoat, you might have to use something like some 1,000 grit wet/dry sandpaper. You could even go to a slightly stronger grit if you had to, but for those small streaks, I think you can get it with some elbow grease. But always try a small test area first to ensure you're happy with the results.

 

[VinceL]

My experience may not be relevant to your situation since I don't see an SWG listed in your signature.

We have a spillover from our fiberglass spa into our fiberglass pool which we run about 7 hours per day. The wall behind the spillover waterfall is tile, and we get a white buildup on the tile. We have a saltwater pool, and in our case the buildup is salt. It takes a little elbow grease to scrub the buildup off.

We have tile around the waterline of the pool so there is no fiberglass exposed above the waterline. I have not seen any lightening of the fiberglass below the waterfall.