can't keep fc up

[delfargo]

o.k., pool gurus...my ph is in the 7.5 to 7.8 range, cya is in the 40-50 range but i can't seem to keep the clorine level up. it's testing 0 - .5 ish. i keep dumping bleach in and it'll come up a bit, but i'll check it later in the day and it's back down to near nothing. i got it to shock levels last week. do i need to shock again? why can't i get it to stay up? thanx for the help.

 

[Guest]

Your pool has a chlorine demand that needs to be satisfied. It might be a nascent algae bloom or a big organic load in the water. What is your CC reading? (I assume you are posting FC readings.)
Shock the pool AND KEEP IT AT SHOCK LEVEL BY TESTING AND ADDING CHLORINE SEVERAL TIMES A DAY SO IT DOESN'T DROP until the CC is 0 and you are not losing more than 1 ppm FC overnight.
Also, if you would put the info about your pool, filter, etc. in your signature it would be helpful.
When asking for help it's a good idea to post a FULL set of test results. The different water balance parameters do interact and sometimes the answer might be in one of the numbers you have not posted. Also letting us know HOW you are testing can be important. (For example, are you testing the chlorine with OTO, DPD, or FAS-DPD or are you using strips? Some of these can 'bleach out' and read low when the chlorine is, in fact, high.)