I am new to the board and have been reading through the amazing wealth of information found here. Simply amazing!
Let me tell you about my problem. We have an 8,000 gallon fiberglass pool. One day we noticed that the walls and floor of the pool had a yellowish ting to them yet the water was still clear. Being ignorant to real pool care since this is the first home we've ever rent with a pool we super shocked the pool. The ting never lifted so I figured this was a different animal than algae.
I started searching and searching for answers and came upon this site. Eventually I learned about iron. I did the vitamin C test and sure enough the stains started lifting. So I decided to try some ascorbic acid. I read about lowering the chlorine levels and the ph into the proper levels for treatment with the ascorbic acid.
So I treated the pool with the ascorbic acid and the stain lifted and the pool was a beautiful Caribbean blue for about an hour. Soon after the pool turned dark green color. I thought this was the iron coming off the walls and now the particles were floating in the water. So I ran the pool for the recommended 48 hours and kept cleaning the pool filter every 12 hours or so. Eventually the water cleared albeit somewhat of a murky clear but I was happy and figured that would filter out with time.
I read about adding bleach slowly because you do not want to shock after treatment with ascorbic acid. First I tackled raising ph and alkalinity and then proceeded to attempt to raise the chlorine level to around 3ppm. I added the recommended amount of bleach to raise the levels. At first when I tested the level was around 3ppm, about 2 hours later the levels dropped back to 0. This was an ongoing battle for about a week.
I was getting increasingly frustrated. I took the water to get tested at a local Pinch-A-Penny and they gave me these readings.
Calcium Hardness 250
The CYA really blew my mind being that high, which I knew was not good. Could that be why the chlorine was not holding?
Anyway, throughout this battle we resisted calling the landlord because we knew he would just take and get the water tested then say shock the pool. That is his answer for everything.
So eventually frustration mounted and we called him he came over took the water to be tested came back with the same results. He said there is no chlorine. We said that yes this is true, we were battling Iron and you cannot have shock the pool for 2 weeks while treating. He said well the pool store says add chlorine and shock and that's what were going to do. So he put the inline chlorinator to 5 but did not shock since he said we had to buy the liquid chlorine.
Now the pool has run for 2 days on its normal 8 hour cycle and the **** yellowish stains are back clinging to the wall.
I realize the CYA is high being 100 and I know that draining the pool is how you correct that.
Even though I know that is too high the pool store feels it is within normal range and thus so does the landlord. But now thanks to his insistance on bumping the chlorine the pool walls are now the beautiful yellowish ting again.
Please, can anyone offer any suggestions or help?