I'm having problem with green pool, I can super chlorinate it vacuum 2-3 days and have water crystal clear and a couple days later green again. I have 18x33 oval above ground pool around 15,400 gallons. I bought a taylor 2006 kit. Last night when i come home everything I vacuumed day before has algae growing again. I check chlorine I have about 5.0 free chlorine then checked combined chlorine when i put drops in water didn't change back to pink so I guess I have no combined chlorine so is this enough to keep algae growing? Ph is about 7.4. Total Alkalinity is about 100. Cya is about 60. I had this problem last week and was fighting it so I drained 2/3 of water refilled had everthing where is should be, checked it friday we went out of town came back Sunday and it was green again. I then pour 5 gallons of liquid chlorine vacuumed it for a couple of day got water super clear and a couple days later green again. When adusting TA i'm using baking soda and ph was a littlle high using muratic acid to lower, I'm weighing all chemicals with post scale and using poolcalculator.com. At this point I don't know what to do, any ideas would help. I have had this pool 15 years and never fought green pool. When i'm vacuuming i'm switching filter cartridges out and letting pump run 24 hours a day.