Can Organic Mud Create Algae


New member
Mar 10, 2017
canyon country, ca
We recently had a bad wildfire (welcome to California) and then mud slides. The first slide was all of the organic ash from the fire. This "mud" made it to the pool. There was about eight inches of mud at the bottom.

We drained the pool and did an acid wash. When we refilled the pool we noticed yellow/brown stains arond the sides of the pool at the bottom where the mud was. we tried a chlorine treatment, but it's still there.

The stains appear to be growing, but it is hard to tell as the stains are visable when the sun shines, but almost disappear when a cloud blocks the sun. Now the stains appear on the walls of the pool (lighter than the stains at the bottom).

My pool tech thinks I need to replaster, but I am thinking it is Mustard Algae and should be treated.

Any thoughts?


New member
Mar 10, 2017
canyon country, ca
I was afraid you were going to ask that :). I do not have any testing equipment just yet. I have a pool service that normally takes care of the pool. I will have to go out and get a testing kit. Is there a particular brand you recommend?

- - - Updated - - -

My main question was: Can the organic material in the mud (oak, sage - Calif Chaparral) produce stains that acid wash can't remove and can this mud cause mustard algae?

I will get a test kit and get the answers you need.

Thank you for your help!!!


Well-known member
In regards to a test kit we recommend the TF100 from or the Taylor k2006C available from amazon. Both have to be ordered online

Organic material itself wont cause algae in the pool. However it would have placed a significant drain on your chlorine reserves. Once the chlorine got low, then the algae would have had a chance to get a foothold

The stains could be organic in nature or could even be iron deposits from the soil.

We have treatments that work for both of these scenarios, but need careful chemical management, using the results from the test kits suggested above

You could try the tests in the link below to see if you can identify the stain.


Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
East Texas
Mud is just that...mud. Mud doesn't cause algae--------unless it contains algae spores. Just because your CCs go up doesn't mean you have algae due to the mud. I'd get that test kit, brush it, and slam it if necessary before anything drastic. The longer the mud or organic material such as leaves sits there, the more likely it is to stain.


Well-known member
May 2, 2011
lebanon tn
Oaks, fears, and redwoods I believe all have tannic acid in them. Creates a tea colored stain. So one answer is yes mud can cause stains. And can act as food for algae and create a bloom if fc isn't maintain d. So you could have so her