Dark Blue streak from side water jet down wall to floor

[calbob]

We had our pool replastered with diamond brite...tahoe blue...after they did a acid wash and I refilled the pool up, I noticed a dark blue streak from the side water jet down the wall and floor...I have brushed and brushed with no luck getting the streak off...Any ideas on what and how to remove this streak. I can see a little mottling going on with the floor, but that is more of a white cloud, and not too noticeable but this streak is dark so it is noticeable

Thanks
CALBOB