Best way to handle stubborn algae spots?

[nickgadna]

Hi all,

Long time lurker, first time poster. Thanks also to the devs of the pool math app I am loving not having to schlep down to Leslies and taking my own measurements with my Taylor kit is super easy. I am a first time pool owner and the previous had let some spots of algea develop, I suspect due to low chlorine levels when I started testing. I have been brushing these with wire brushes and they refuse to come up. The only thing I found that worked on one of the spots was taking a chlorine tablet and rubbing the spot with it (picture with the red circle). Any other strategies so I dont have to dive down in the pool and do the same on the other spots in the deeper end? If I brush with a wire and SLAM will that work? I have brushed and then shocked to no avail and it seems that some come up while others dont. Looking for the best way to address.

Latest chemistry:

4.0 FC
0.2 CC
7.7 pH
90 ppm TA
360 ppm CH
55 ppm CYA
0.22 CSI
88 degrees

 

[Texas Splash]

If I brush with a wire and SLAM will that work?

It might if the algae isn't already becoming embedded under calcium scale. Are you familiar with our SLAM Process designed to kill & remove algae? If not, you might give that a try by following that page carefully. Even once you pass all 3 SLAM criteria, organic stains can take a while to go away. Maintaining the proper FC level as noted on the FC/CYA Levels with consistent brushing is key.

Welcome to TFP!

Pool Care Basics

 

[nickgadna]

Thanks @Texas Splash ... I think I may have found the culprit. Do I just unscrew and remove this light? Obviously flip the breaker first right?

 

[nickgadna]

Also, i've been balancing the water for a bit now and dont think I am going to fail the overnight test, my water is also clear. is slamming the right method when this is true? Should I be doing it just to clear up these spots and around the light?

 

[Texas Splash]

Do I just unscrew and remove this light?

LED lights vary. Usually we can remove the covers but we don't remove the fixture that's against the wall. Yours is different than mine so we're in some uncharted waters I'm afraid. If you can't figure it out let me know and we'll see if we can get a field tech member to respond.