Hi folks. My pool started to turn green Wednesday and is full green today. My marriage may depend on this as my wife has a party planned for Thursday so any help would be appreciated.
As background, I live in Fresno. Temp has been 105-110 for the past few days. Its 107 today and forecasted to drop to a cool 100 by the end of the week. I moved into the house three years ago. The first year I tried to handle the pool myself with the help of my local pool supply store. I ended up with an algae problem that I treated with algaecide. It would go away for a few weeks and then come back (I might have let the Chlorine levels drop). I treated with Algaecide again. I think this happened three times before winter. In the spring, I hired a pool service. They told me that I had "killed the water" with the result that it would not hold chlorine (not sure what they meant but after reading on this site I am guessing that my CYA was too high) and that the pool needed to be drained. We drained the pool and started over. I also replaced my cartridge filter and purchased a new Hayward vac.
The pool service has handled the chemicals since the refill. We did not have an algae problem for the first year and a half. My wife noticed the pool going a bit green on Wednesday. As I couldn't find any evidence that the pool service had come, I thought that maybe the chlorine was low but I wasn't smart enough to bring in a water sample for testing. I put two 10 oz packages of Genesis shock (fast dissolving trichlor) Thursday morning hoping to hold off the algae and called the pool service (I realize after reading here that this was probably a mistake). As I said, the pool service came out Friday but the pool got even greener.
On Saturday, I found this site and, after doing some reading, ordered a TF100 test kit but this won't arrive for a few more days. I also read the very helpful sticky on defeating algae. I dumped 2 x 96 oz of 6% bleach in the pool yesterday afternoon. This morning I purchased a basic OTA test kit from the pool store and had them test the water (not ideal but it will have to do until the TF100 gets here).
FC - 5
CC - 5
pH – 8
TA - 90
CH - 200
CYA – 99
If I understand the CYA/Bleach table my target FC is 12 and my shock is 39 so I am well below shock amounts.
I am not sure how to proceed at this point and have some questions.
(1) I do not understand why the CYA is so high given that the pool was drained just last year. Its really weird to me but I do not know what the pool service has been dumping in there. I read on this site that genesis raises CYA so maybe that is why but I haven't put that much in. Does the CYA go down overtime naturally? Also the guy at the pool store said that 99 was an okay CYA number but that doesn't sound right. Does recommended CYA vary by region.
(2) Do I need to try to drain some water to bring CYA down and if so how much water do I need to drain.
(3) The pool calculator says that I need to add 5 x 96 oz of bleach! Can that be right?
(4) Is there anything that I can do to clear the problem so that my wife can have her pool party? If not, do any of you have room on your couch for a few days?
Thanks in advance for your advice.