Newbie with green/yellow stains

[PoolPunk]

Hello TFP! Thanks for having me.
I just moved into a new house, and it has a 13,000 gal pool. I've never had a pool before.
I've balanced the water, and it is crystal clear.
However, I have these green/yellow stains that I just can't get rid of. They are around the main drain.
They are pretty substantial in size. About 2-2.5 feet ALL THE WAY AROUND THE DRAIN. I've been scrubbing it with my pole brush, and it seems to get a little lighter in color, but, it looks terrible. What can I do?
Thanks for any advice. I'm all ears !

 

[Bama Rambler]

Welcome to TFP.

What is your pool construction?
Can you post a set of test results?

If it's plaster you can take a trichlor tablet and hold on the stain foe a bit and see if it lightens it. If it does, then it's organic and holding your FC on the high end of recommended for your CYA will lighten it over time. If it doesn't help then take a vitamin C tablet and hold on it. If that lightens it then it's a metal stain and a AA treatment will most likely clear it up.

 

[PoolPunk]

Thanks for the quick response. I really appreciate it.
I'm not sure what the pool construction is. Concrete, maybe?
Again, I'm a newbie that knows virtually nothing about pools. How long do i need to hold the tablet on the stain?
(I'll be holding my breath since it's 6' below surface)

 

[Bama Rambler]

Use the brush or vac head to hold it down there. Start off holding it less than a minute. You'll know pretty quickly if it's working.

 

[PoolPunk]

Perfect. Thank you again. I'll post results tonight.