Mustard or green algea

[Tommygarry1]

Hi TFP community. I noticed some spots on my walls. Nothing obvious to the regular bystander, but I am very analytical with my pool. When I brush it, it comes right off. Later on, I notice that it comes back. From what I read, this could be a little mustard algea, although I also read that is rare...especially in the NE where I am in NY. My water is crystal clear, passes the over night test, and has CC of less than .5. Again I will stress that I notice it but most don't or won't.

My readings are attached.

My thoughts are this does not qualify for a SLAM. I would hate to have to drive FC up to 31 and then not be able to use the pool for a while because of the need to wait for it to drop. I get that it is technically safe to swim below shock levels based on CYA chart but I just don't feel comfortable letting people and kids jump in the water with FC levels way above 10.

Any thoughts. Maybe a little Cal Hypo and get it up to 10? Thanks

 

[Texas Splash]

Since you stated that you have passed the Overnight Chlorine Loss Test, I don't see a need to go into a SLAM Process at the moment. Increasing the FC to 10 really won't accomplish anything anyway. For now I would continue to monitor. Brush that area a bit more than others and watch for any other indications it might actually be Mustard Algae (or regular algae). Only then if you do, or later fail the OCLT, would I take it further.

Mustard Algae

Today We are going to show you how you can get rid of mustard algae in your pool. By following the steps in this guide and with no expensive chemicals.

www.troublefreepool.com

 

[mknauss]

Curious, how did you get a result of 5.3 ppm FC?

Also, CC is not likely the same as FC. Hopefully CC is at or near 0.

 

[Tommygarry1]

When I use my tailor kit I tend to round off and split the differences with the colors. Probably shouldn't do that but it's just to have it. So I guess for all my measurements just round up. I always just. And combined chlorine as the same. That's my mistake. My free chlorine is equal to my total chlorine. My CC is less than 0.5

 

[Tommygarry1]

Sorry for any typos as I am dictating

 

[Tommygarry1]

Since you stated that you have passed the Overnight Chlorine Loss Test, I don't see a need to go into a SLAM Process at the moment. Increasing the FC to 10 really won't accomplish anything anyway. For now I would continue to monitor. Brush that area a bit more than others and watch for any other indications it might actually be Mustard Algae (or regular algae). Only then if you do, or later fail the OCLT, would I take it further.

Mustard Algae

Today We are going to show you how you can get rid of mustard algae in your pool. By following the steps in this guide and with no expensive chemicals.

www.troublefreepool.com

Update on this thread. Still saw some of that greenish/yellowish stuff on parts of walls. Again, not an "eyesore." My wife does not notice. Brushes right off. Passed all 3 tests. Latest numbers...plus I decided to massage my filter with a nice backwash. Off to play golf.