Quote Originally Posted by medstudy
I have never had the problem I have now and it is very frustrating.
You are in the right place.

Every day when I check the chlorine level it is on zero.
How are you testing? (i.e. test stips, 5 way kit with drops etc.)
I keep my automatic feeder full and turned all the way up and I have started placing 3 tablets in the skimmer.
So, you are using both an automatic feeder AND putting pucks in the skimmer? This is probably way to much.
(I have a 20,000 gal pool). I have been shocking it about 2-3 times a week in an effort to get the levels up (using about 4 pounds of trichlor). On the evenings I shock, the next am level is still zero.
Something is obviously chewing up the chlorine. It could be Algae, chlorine, phosphates, ammonia, the sun or a host of other possibilities as well as the possibilty that you have a lot of chlorine and it is bleaching out your test.
My stabilizer level is normal. This is becoming more expensive as I am running through my shock. What in the world is going on?
What is "normal"? First thing you should do is post some numbers for FC (free chlorine) CC (combined chlorine) PH, ALK (alkalinity) CYA (aka stabilizer or Cyanuric acid). These numbers should come from a drop based test kit or your local pool store. If you go to the pool store, don't let them sell you ANYTHING! The people here can help you for a lot less money and a LOT less time. Post your numbers, don't add anything else and tell us what all you have added to the pool when posting (i.e. dichlor shock, algaecide {brand/type}, clarifier etc.) Also tell us what type of pool you hace ( gunite, vinyl or fiberglass etc.)
Again, if you are tired of throwing money at your pool to no avail, you have come to the right place. I assure you, if you follow the procedures recommended here, your water will be safer and clearer than you have ever had.

Dave