This happened the first year I had a cover on. I've pressure washed, scrubbed with a cleaner for patio, I get very little change. Any ideas how to fix this? It's literally the outline of the cover. 
Discoloration on concrete
- Thread starter Kegman
- Start date
- May 3, 2014
- 58,633
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
We see that a lot on the forum. I believe the exposed concrete (darker) is dirty -- but not sure you can clean it well enough to make it match.
What did you try and wash, the bright or the dark as Marty asked ? I see this every year as the dirt builds up over the winter due to no rain. I pressure wash and it brings it back to match the clean area that was under the cover. You will need a lot of pressure and have the wand set to only an 1" wide spray and be very close to the surface, slow going and will take many hours. I am experimenting with a sealer this year to see if the "clean up" time can be reduced.
Be careful with a pressure washer on concrete. The jet tips can etch the concrete. A 40 degree tip is suggested for cleaning. I'll be cleaning mine this weekend with a new cleaner. I'll let you know if that helps.
Similar threads
