need help with free chlorine

I opened up my 20 x 40 inground pool 3 weeks ago. No matter how much chloring tabs I put in, something is gobbling up the chorine such that when I test for free chlorine, it reads zero! took a sample in to the pool place who stated that I have extremely high nitrogen amonia which feed on the chlorine and form choramines. I have tried flocculants and vacuumed to waste several times, reshocked the pool with up to 12 bags of chlorine with the same results. Can someone pls help? This is getting expensive. Is my only way out to drain and refill the pool?

How does your water look? Do you have test results from a drop-based kit for pH, T/A, CYA? My guess is that you have no CYA in the water, which means that not only is the "goo" in your pool using up your chlorine, but the sun is consuming the rest of it, as well. If 0 CYA is the issue, then you need to go to WalMart, Lowe's, Home Depot, Leslie's, or somewhere and buy CYA (also labelled as stabilizer, conditioner, or balancer, but cyanuric acid or isocyanuric acid is the active ingredient.). Add the label dose to get your pool to 20-30 ppm, either through your skimmer, or in a sock tied in front of a return, and then don't backwash or retest for it for about a week. At that point, you should start to see your pool holding some chlorine. In the meantime, though, you're going to have to add chlorine daily to keep your pool from becoming a swamp.

If 0 CYA is not the issue, then the only way we're going to be able to help you figure it out is with some good test numbers.


Janet

First thing is to check your cya, but there could also be something in the water causing you to have a high chlorine demand. Get the water in balance first because a low ph will cause you to go through chlorine like crazy as well.