Hello everyone, this is my first post and wanted to share what I've gone through getting Baquacil out of my pool and killing off the green alage. This web site has been so helpful and I'm thankful to have it while searching the Internet for help.
My pool is 13,500 gals vinyl with a 1 HP Hayward Superpump and a 244T sand filter and we have been on Baquacil for 1.5 years. I never liked it but my husband got sold on it through the pool company we were dealing with that it was much better to use, especially indoors than chlorine. I never felt the pool was safe to swim in so in reality I haven't used my pool since Baquacil was introduced in it, for the most part because the algae would creep in here and there too often.
I stop putting anything in the pool about a month ago to reduce the levels of Baquacil before starting the converting process. Well, when I did that the algae grew, grew, grew. I would still brush several times a day and backwash often and of course get water tested with my Baquacil test strips and from the pool company. Both testing methods said my Baquacil levels were still really high all through out the month. I decided to take the plunge and went with GLA super shock and doubled it. It started killing the algae right away and the pool turned from an emerald green to a lighter blue green color - no browns, or other strange colors. I could not see the bottom of the pool even in the shallow end. I'd brush anyway towards the main drain. I did not see any goop or strings in the water so I thought well maybe I didn't have as much Baquacil in the water as the tests were stating. I didn't have a test kit at all and after two days nothing was changing - it stayed the same after the first super shock. My pool company guy said to shock again and once again double the amount from what would be normal. I did, and when I did that the water turned brown and a sick yellow -- I was concerned and my pool guy said he didn't understand why it would turn yellow. So, I went to my local pool supply, they tested the water sample and said my CYA levels were 100 with no FC showing, Baquacil was 6ppm, 0 metals. They said I had chlorine block and I would have to drain the pool. That caused me some real concern since I had a vinyl liner. I purchased a Pentair Pro-11 test kit and off I went to drain water. I drained my pool down to 18" all the while keeping the vinyl liner wet to avoid any shrinkage. Refilled the pool (water still looked an ugly brown/yellow) tested the CYA levels which showed at 40 and shocked heavy using the pool calculator I found on this web site. I continued to test all through the day Friday, and Saturday and the the chlorine levels were holding at least 10ppm or greater (test kit only goes to 10ppm). I still could not see the bottom of the pool. However, today (Sunday) I can see the bottom of the pool and can see the main drain a little bit in the deep end. I backwashed and the most awful goldenrod color came out - backwashed 5 mins, rinsed, 5 mins.
The pool water is not yellow anymore and is still very light green, or maybe really a blue green.
My question I have - is this yellow brown coming from the Baquacil? I also notice in the skimmer the water has some deep yellow still and floating junk. Should I shock again or pass on that and wait since the chlorine level is holding at least at 10ppm or greater?
Plus, I was wondering what type of chorine I could use since I really don't want the CYA levels to increase. We had always used the 3" tabs in a inline chlorinator - I now have a new offline chlorinator but I've kept it empty through this conversion process and getting the algae removed. Any input will be helpful, and sorry this was so long, once again thank you.