Finding black mold in the pool skimmer 3 weeks after closing

[mvpileg]

Hey folks, first year pool owner here. I had my pool closed through a service 3 weeks ago and this morning it looks like mold is growing in the skimmer.

Is this normal? And do I need to worry about this spreading to the rest of the pool over the winter?

 

[ajw22]

What was the water chemistry at close?

I would pour a bit of liquid chlorine in the skimmers and stir the water and see what that gunk does.

 

[mvpileg]

I appreciate the feedback! I will try adding liquid chlorine

Here are the last water chemistry levels, but they did add their own chemicals during the closing process and I'm unsure how that affected the levels:

Alkalinity - 105
pH - 7.6
Total chlorine - 2.1
Free chlorine - 2.1
Hardness - 200
Cyanuric Acid - 30
Salt - 3280

 

[ajw22]

That is not from your own test kit so the accuracy is questionable.

Your FC was too low for your CYA level and you probably had algae in your water at close.

Our closing recommendation is close with algae free water following the SLAM Process and then possibly use Polyquat 60 algaecide as insurance.

It is too late now for you but get your own test kit - K-2006C or TFT Test Kits and begin following TFP methods next year.

Pool Care Basics Archives

Your one-stop shop for all things TFP to include: ABCs of Water Chemistry, Recommended Chemicals/Levels, Test Kits, Troubleshooting, and much more!

www.troublefreepool.com

 

[mvpileg]

Yeah ordering and learning to test has been on my TODO, but we moved into the house with this pool in August and since things were busy, I opted to let the local pool company measure it. I will order the test kit for next season.

For this winter, is there a concern of this spreading to the rest of the pool? And anything I should do if I start to see it happening?

 

[ajw22]

Get your test kit and deal with it at your spring opening.