Gunite Inground Pool approx 18,000 gallon 16x32 (3.5' shallow end and 8' deep end)
Sand Filter
Currently Using 3" Tabs in two floaters.
Test with Test Strips - According to test strips my ph is 7.2, free chlorine 0, alkalinity 80, stablizer 30-50

I have had a hard time maintaining free chlorine. I started to see slight algae on the walls about a week ago so I used some algaecide. I think I used too much algaecide.

I then bought some granulated chlorine and the 2lbs of chlorine was gone by morning and I shocked the pool twice (1lb bags each.) and each time the free chlorine level was gone.

I then went to Leslie Pools to get my water tested - 7/28 Per their water analysis form:

Free Chlorine - 0
ph - 7.4
Total Alkalinity - 100
CYA - 0
Calcium Hardness - 200
Phosphates - 300

Yesterday 4 hours apart I did the following:
- Added 4lbs of Stabilizer & Conditioner (HTH brand)
- Added 1/2 bottle of (67.6 fl oz) Natural Chemistry PHOS free from Leslie
- Added 3 bags of Leslie Shock

This morning I tested my water and I still have no free chlorine. My testing strip looks just like it did prior to doing the above.

Any help would be appreciated.

Thank you,
Debbie