One more place to look for algae.

[Flying Tivo]

Just when you think you looked everywhere, BAM, the weir door foam. Never imagined i had to look there. Never had dull water just FC loss of 4-5ppm with cool weather and low UV index. Started cleaning the skimmer for a complete brushing and found this. I would recommend finding a higher density foam, even an EPO which has less cavities where algae can hide.

 

[Mdragger88]

Good looking out!

 

[Richard320]

Adding this to my useful links.

 

[Snieggy]

I am currently SLAM'ing and came across the same exact thing yesterday! I soaked the foam in a bowl w/ bleach water. I'll be keeping a close eye on it to see if anything comes back.

 

[KristaM78]

Just when you think you looked everywhere, BAM, the weir door foam. Never imagined i had to look there. Never had dull water just FC loss of 4-5ppm with cool weather and low UV index. Started cleaning the skimmer for a complete brushing and found this. I would recommend finding a higher density foam, even an EPO which has less cavities where algae can hide.
View attachment 142838View attachment 142839

Where did you get this foam?

 

[KristaM78]

I am currently SLAM'ing and came across the same exact thing yesterday! I soaked the foam in a bowl w/ bleach water. I'll be keeping a close eye on it to see if anything comes back.

After soaking in bleach did your slam go better? I’ve been slamming for a week. Could not figure it out. Today, I discovered the foam on my door!

 

[Flying Tivo]

It was a packing foam i got with the mail, so could not tell you. Probably an arts and crafts store.