First year using the TFPC method - which is AWESOME!!!! I was cleaning the waterline with a microfiber cloth yesterday, when I noticed this weird "dirt", only at the deep end. I am posting photos which show what it looks like before and after wiping with the cloth, as well as the stain it leaves on the cloth after wiping. It is very difficult to get it off the walls - it just wants to smear. Is this pink algae? Has anyone ever seen anything like this? FWIW, here are my current test results:
FC 6
CC 0
PH 7.8
TA 90
CH 250
CYA 60



FC 6
CC 0
PH 7.8
TA 90
CH 250
CYA 60


