Swimming Pool Algae

[jgy2001]

Because of algae, we shocked the pool and plan to drain.
After we refill with fresh water, we use the 3 inch chlorine tablets in the chemerical in-line dispenser, with opening gap setting at 3 to 4%. Also, we heat the pool to around 84 in the days we swim.
Should be add Clorox Green Algae eliminator at this time? For every 1000 gallon of fresh water, how much should we use? Should we add this in the same in-line chemical dispenser also? Thank you for you advices.

[Denniswiseman]

Stop using Trichlor pucks and use liquid chlorine plain bleach, you probably have excessive CYA causing your chlorine to be ineffective

Excessive CYA renders your chlorine ineffective and you have to use more to get the same sanitation
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm
To reduce your CYA you have to do a partial drain and refill
Continuous use of Trichlor/Dichlor will raise your CYA which means you have to raise your chlorine level as well

You need some CYA, about 40/50 as indicated in Chlorine / CYA Chart

[Teapot1]

You shouldn't need to drain and refil because of simple algae but as Dennis said check the CYA level, this chemical controls your pool and very important to test it or get it tested AND not with test strips as these just dont work well for CYA stabiliser

[jgy2001]

check the readings around 2pm:
pH 7.2
TA 160 ppm
CYA 0 ppm
TC 0 ppm
FC 0.1 ppm
TH 250ppm
May be this morning was very sunny, so we assume the sun burn off the chlorine?

[Denniswiseman]

You are showing no CYA have you had fresh water in as it's not possible using Trichlor / Dichlor to not have any CYA
If you have changed the water get some stabiliser quick or your chlorine being burnt off will increase your chanc of algae

[young707]

Chorine Stabilizer is Ayanuric Acid, correct? How much the pool pH level will be caused even more lower more?

[Teapot1]

Cyanuric acid, yes it can buffer the pH downwards from memory pH 6.8 certainly helps offset the buffer effect of too much TA