Today I began the conversion from Baqua to Chlorine in my 8000-gal AG Doughboy. After reading the how-to directions here, I bought shock from my local pool store. I use Jason's calculator and found that 1 gallon of 10% bleach would raise the FC level from 0 to 12, so I poured it in! The water turned a creamy yellow. After 2 hours I tested and found the FC to be 0.5. I poured in another gallon and just for grins, I re-tested 15 minutes later...FC=1! Still creamy yellow...what's happening?

Welcome to TFP!

That is all normal. Enjoy the strange colors while you can, in a week the water will just be the same old sparkly clear all the time

There is a very rapid reaction during the first day(s) that uses up chlorine only a little slower than you can add more. This reaction turns the water all kinds of strange colors. Yellow isn't the most common color, but one of several possibilities.

You want to keep on adding FC up to about 15 ppm, wait at least half an hour, test the FC level to make sure the chlorine is still all going away, and then add more chlorine. The pump should be running this entire 24/7 time. After a noticeable number of times you will still have some chlorine after half an hour or an hour and at that point you can slow down and add chlorine less often.

Okay...I'm nearing the end of the second day of the conversion in my 8000 gallon Doughboy pool. Things are looking up. The water is no longer the color of cream corn. I added enough bleach to finally get a reading above 12 for Free Chlorine. Now my water color is more like lime jello, but it's beginning to clear. I have to say that testing and back-washing every 2 hours has helped tremendously! My pump loves it when I do. So far I've used 8 jugs of 1.42 gallons of 6% bleach and 4 gallons of shock (10%). It took adding 4 jugs (about 6 gallons) of bleach at one time to finally get the correct chlorine level. Looking forward to the next color change!

Finally getting there...I've taken pictures which I'll post later. I awakened to a nice surprise...the pool bottom could clearly be seen. There were little bits of brown stuff, but the water was clear although a light green in color. I brushed the bottom and sides of the pool and the brown stuff is now gone. I bought a good test kit, but I've been using strips to monitor the CC's and FC's because they are easy to use and been testing often. It's been cloudy this AM and the chlorine levels are high, but the sun is now shining brightly so I expect to see them fall quickly. It's nice to finally see the water surface shine!

Congratulations!