What is this spot?

[totalnoob]

Just spotted couple of these spots in my pool with one being the biggest, and couple others are small. Any ideas on exactly what this is and the best method to remove the spots?

Thanks.

 

[mknauss]

Is it green? Looks like algae -- run a OCLT tonight?

 

[totalnoob]

Is it green? Looks like algae -- run a OCLT tonight?

Yes, it is greenish color, and if I try to scratch it, nothing happens.

Still OCLT will work?

Thanks.

 

[mknauss]

Yes. Do you have a pool brush? Try that on it. Do a OCLT tonight.

Take care.

 

[totalnoob]

Yes. Do you have a pool brush? Try that on it. Do a OCLT tonight.

Take care.

Yes, I do have a pool brush, but it doesn't help.

Will do OCLT later (going out of town for some days).

 

[zea3]

Try rubbing it with a chlorine puck and see if it lightens any.