Bright Yellow Staining Above Waterline in Rotomolded Spa

[Ericwood73]

I have a rotomolded spa with bright yellow staining just above the waterline as can be seen in the picture. I tried Oxy (mixed with a little water to make a paste troweled on and let sit until hard then scrubbed off), boat hull cleaner, vinegar solution with a magic eraser (though I didn't wet the sponge, just sprayed the vinegar on and then rubbed with the magic eraser). Nothing has had any effect at all. Most of the advice I read is for acrylic hot tubs and I'm not sure it applies to rotomolded plastic. Has anyone had any experience with this sort of stain on a rotomolded tub and if so, did you find anything that would remove it.

 

[JodieM]

Have you tried doing a purge with Ahh!some? We get the yellow stain every winter bc we don’t use our hot tub. We clean and purge the lines in the spring and then replace the water to get ready for warm weather use. Letting the tub soak during the Ahh!some cleaning time and then scrubbing removes the stain for me. Our inside shell is pale gray.

 

[Ericwood73]

I have not done a purge, because I already drained the tub. I see ahhsome makes a shell cleaner. I wonder if I could spray that on and let it sit and then scrub it off.

 

[JodieM]

I have not done a purge, because I already drained the tub. I see ahhsome makes a shell cleaner. I wonder if I could spray that on and let it sit and then scrub it off

I use the gel in the jar. I suppose you could apply to a sponge and work it around, however I’m not sure if getting it into the water would ok since it’s created to use to clean before a fresh fill.
@Ahhsomeguy any suggestions for Eric?

 

[Ahhsomeguy]

I would recommend our spray cleaner for that job. It is specially formulated for gunk above the waterline.

 

[RDspaguy]

So, did it work?