Mustard algae questions...

Looks like I may have mustard algae :eek: See pics (looks a lot worse and more in real life). I was getting spots and a bit clouding a couple weeks ago so I SLAMMED and passed the tests but sure enough it's been gradually coming back and it got really bad quickly yesterday. So I'm currently SLAMMING and brushing everywhere 2x day and it's slowly improving. I want to really kill it this time so I have some questions.
1. Should/can I use my robot vacuum during slam? Could it be harbouring algae inside the robot? Do I need to wash him in bleach too?
2. After I pass my slam tests, how long do I raise FC to mustard shock levels?
3. I removed my ladder for now, does it need to be washed down in bleach? Same for all pools toys, do I really need to clean everything in bleach? I have a lot of kid pool toys! :oops:
4. There is one spot in particular in the shallow end that goes yellow fast and furious, is there anything special I should do to that spot?
5. Anything I'm missing? What about in jets? Or skimmer area? Extra scrubbing?

How long has it taken others to clear up properly?

Before slam:
FC: 6.5 (was recently keeping higher when I noticed issues starting)
CC: 0
Ph: 7.3
Alka: 70
CYA: 55




Well-known member
Aug 8, 2018
Plainfield, IL
Hi Beth

Check this Pool School guide - Mustard Algae
Most of your questions are answered there. Regarding pool robot, I don't know what type of robot you have but if it's anything like popular Polaris, I would use it.
My take is - any extra brushing/scrubbing is definitely beneficial especially during SLAM. And you can easily accomplish it by running cleaning cycles with your robot in addition to manual labor, lol