What's this stain

Is this what you guys call tanin stains? They are all over the court. I post treat with an xjet!
Customer is happy with the product just wondering if I could get them out someway

Tannin stains are from leaves so would be brown. Some tannin stains are even shaped like a leaf from it being stuck to the concrete while wet. Those spots there almost look like it could be from some type of oil or something. When I say oil maybe something like one of those citronella candles in can. Sometimes people leave the lid off, they fill with rain water, and either someone kicked it over or it fell of a table. They could’ve even used that area to have a fish or turkey fry and those stains could be from peanut oil bubbling and splashing over when they put the turkey in the grease. It can really splatter if you don’t dry the turkey off or if you lower it too fast. Do water droplets just sit on top of those spots or do they soak in like the rest of the concrete?

You’re just going to have to try some different chems to see if anything works. I would start with a degreaser. Might need hot water depending on what it is.

I read too fast and missed the part where you said it’s all over the court. It might be a botched sealer job.


Yeah I’m not going to do anything with it, they are happy with the outcome.

I could tell they had some equipment there before and thought done might be oil.

The court had bad drainage, and lots of shade so I could barely get it to dry before I posttreated. So I’m not sure if water just sat on too of those spots