Think I have mustard algae

Fairly new pool owner after we bought a house who is trying to take care of it on my own. I have had this brown algae forming in my pool steps and walls lately and it's been easy to brush away, so I just assumed it was dirt.

So I've been trying to get my chlorine levels up but even though I dump in enough Cal Hypo each night to get it up to 3 ppm the next morning I'm pretty much at zero still. I've tested my ph with a test kit and it's fine.

After a bit of research I think what I have is mustard algae and not dirt!!

I found a good youtube video where a guy uses Yellowtrine to clear up mustard algae. Just wanted to see if there are any cons or tips to following that approach.

Thanks in advance!

Dean

Depending your stabilizer level, you'll need to get your chlorine level anywhere from 10 to 25 ppm to kill algae. 3ppm won't cut it.

I suggest you do some reading on our sister site, poolsolutions.com It's free.
Click on the left on pool guides and look at the algae killing demo.

Do *NOT* use Yellowtrine: it's sodium bromide. Using bromide is an old-school method of dealing with problems with the chlorine/stabilizer ratio . . . but it leaves you stuck with a bromine pool that will consume chlorine at an incredible rate. Eventually, the bromide is converted to bromate, but until that happens you're going to suffer.

Instead:

1. Read the "Best Guess" page, linked below

2. Order a K2006 kit from Amazon (also linked below)

3. Meanwhile, DOUBLE your chlorine input each evening . . . but use plain storebrand 8% bleach. If you keep using cal hypo, you may end up with calcium that's too high, and very difficult to remove. Brush the pool AFTER adding the chlorie

4. Report test results from the K2006 ASAP, particularly your stabilizer level, which is the determining factor in knowing how to manage mustard algae.

Most important for getting rid of yellow/mustard algae is to completely eradicate it. That means getting behind light niches and under removable ladders and other shady areas, especially with poor circulation, where the algae likes to hide out and grow. This algae doesn't like direct sunlight. It requires roughly double the active chlorine level to kill it compared to green algae. You also need to disinfect your pool tools like poles and nets so can put those in the pool at least part of time that you have an elevated chlorine level. Worst case, you can use a phosphate remover, but if you eradicate it then you won't need to worry about phosphates and having to buy another product to maintain your pool other than chlorine.

Our pool has had recurrent mustard algae for the last couple years and I have been unable to eradicate it with very high FC levels for extended periods of time and daily brushing. I suspect that it has found refuge in our solar heating panels. This summer I'll try reducing the phosphate level.