Hello everyone....new here and hoping to get some help..
Been reading the forums for the last 2 weeks and I still can't figure out why I still have black spots on bottom of pool..
I have a 21' AG pool with a sand filter...(about 4 years old)..and one of those nylon socks for the skimmer....been using chlorine capsules that I put in the skimmer and lasts about 2 days...
So after doing lots of reading....I went and tried the bleach method....poured 4 x 5 litre jugs of bleach in 3-4 days....1st jug I poured in the late evening....and then in the morning...some of the black spots seemed to have gone away and the pool seemed cleaner....then it rained overnight...and the black spots came back..(even more this time)...not knowing my cholrine levels....I added 2 full cups of granular chlorine and passed the robo-kleen vacuum...kids went swimming this afternoon and the pool was fairly clean....so tonight...come back home and the pool has the black spots again!!!!!
bought a 20$ test kit and these are my readings
Alk-between 120-180 (done with test strip)
ph-- test strip indicates 7.8 and test kit about 8.0
The more I read...the more confused im getting!!!...I added 2 cups of chlorine this morning and a couple of hours later....test says I have no chlorine...