I just moved into a new house. In addition I'm new to maintaining a pool.
I thought I had an algae problem, light brown stains on the floor that appeared to be growing thought-out this older concrete pool, so I shocked the pool. Two small sections looked to be blackish? The water is clear. I bumped the chlorine up to 24 FC and lower PH to 7.4 and started to scrub with a metal brush, but there was no notice improvement, three days later the FC is currently at 18. The CYA is down to 50 due to rain and some draining / filling of water.
It's an oval concrete pool about 40X18 with an 8 1/2 foot deep end.(est. 28K gallons?) The pool readings were initially below when I started the shock:
FC - 1.62
TC - 1.80
PH - 7.8
Alk - 115
Hrd - 150
CYA - 60
All readings are per a color Q pro7, left by the previous owner. The shock readings may be subjective, as I read the Q has limits of 10 concerning FC levels. ( one must measure 1/2 cap full of the test bottle (10ml) and then multiplied by five). I'm not confident in the readings, as they tend to very if I test back to back. I have ordered a new test kit to confirm the readings.
If it's a metal issue, would the shock have worsened / contributed to the staining? Vitamin C seemed to help the staining on my stairs?
FYI - The pool "guy" came by today to help fix a problem with a leak in the Polaris pump and stated that he thinks that it's metal staining.
28K gallon concrete pool ? - Built 1974 (re-conditioned 2002?)
Polari's pump and cleaner
De filter / 2 hp pump
Hayward gas heater
What's my best action to fix the metal staining? Similar to chlorine there are so many options...
Thanks much - Just learning