Drain and Refill Done

[xiaobulu]

I drained 75% of the pool water to lower CYA and CH.
Before:
FC: 0
CC: 0
TC: 0
pH: 7.4
TA: 130
CH: 600
CYA: 130
Water is clear. Scaling with yellow algae imbedded.

Tap water:
pH: 7.5
TA: 200
CH: 200

After replacing 75% water:
FC: 3
CC: 0.2
pH: 7.7
TA: 170
CH: 290
CYA:40
Water is clear. Yellow algae still present, but seems reduced much.

Actions:
added dry acid to reduce the pH. (target 7.4)
added chlorine to shock level. (target 15)
Leave the fountain on to aerate.
Leave the pump on.
Will brush once a day.

Am I on the right track? Thanks everyone for your inputs.

 

[257WbyMag]

Yes. Although I would add that if you are testing your chlorine levels using a 25 ml sample, you would be best served switching to the 10 ml sample as it saves you reagent. There really isn't a need to have accuracy down to 0.2 ppm. 0.5 ppm increments will always suffice.

 

[xiaobulu]

Yes. Although I would add that if you are testing your chlorine levels using a 25 ml sample, you would be best served switching to the 10 ml sample as it saves you reagent. There really isn't a need to have accuracy down to 0.2 ppm. 0.5 ppm increments will always suffice.

Good tip. Thank you!