Cancer looking stain...

[dsatexas]

Howdy all, discovered a new stain that I'm curious about; it's about a ft below water level around deep end; center is black, about dime sized, and rust looking stain spreading out in mostly a up and down direction from the center of black cancer lookin thing. As I know i have a small leak somewhere, could this possibly be the source? gunite surface deteriorating in that spot? regardless of whatever it is, am alarmed cuz it wasnt there a wk ago.

still new here and attemtping to fix profile, but is IG ~15K gal pool, swg, water chem levels are fine (i monitor it pretty closely). no idea how old pool is but previous owner kept up on property pretty well. is really nice backyard and pool and love it.

Have a great wknd y'all. Its a hot one here in Tx this wknd. Stay cool!

 

[zea3]

Hi, welcome to TFP! Any chance a piece of iron or some fertilizer containing iron was dropped in the pool? Test results give us the information we need to troubleshoot pool problems, so if you could post the results of your most current testing it would really help us out.

 

[dsatexas]

Latest #'s from Monday
FAC 3
TAC 3
salt 4300
CH 170
CYA 40
TA 90
PH 8
copper 0
iron 0
Pho 100

salt is high due to me assuming chlorinator was correct and me trying to get salt level back above 3000. Obviously it is way off. Not sure if this is due to me fixing my own circuit board or not little over week ago. Not sure what to do about the chlorinator. Wondering whether there's a way to reset it or recalibrate it.

anyways..the "ulcer" as my wife calls it, looks about the same this week.
appreaciate any suggestions.