I have a SWG 25K gallon pool, built in 2003, that was acid washed in May of 2009. For the whole of 2009, the pool was great, just required the continual addition of acid as the pH had a tendency to climb.
When I closed the pool, all chemical levels were within range. Plus I have an automatic pool cover, so the pool gets sealed pretty tight with very little water/contaminants entering.
When I opened the pool earlier in May, the water was pretty clear, but the sides of the pool were covered in little white crystals. They brushed off easily. However, my steps are now very rough, about the consistency of 80 grit sand paper. They were so smooth when I closed. Plus the pool cleaner is picking up a lot of these white crystals. They look like pure white sand, don't taste very salty, and crush into powder pretty easily.
When I opened the pool, initial tests showed high pH (8.8) and high TA (180). I only had to run my SWG on super chlorinate for 2 days to get FC to start registering.
So what did I do wrong and what do I need to do to correct it? Below are my current pool chemical readings. I have the TF-100 kit, along with a LaMotte digital reader (which I trust with having the highest accuracy):
- Water is currently 80 degrees
- Salt is at 3800 ppm
- pH is at 7.0 (LaMotte states 7.1)
- TA is between 70 and 80 (solution turns pink at 7 drops, darker pink at 8 drops, no change in color with additional drops)
- FC is at 1.0
- FC using DPD states chlorine at 2.0
- CC using DPD at 0.5
- CH is at 370
- CYA is <20
- Phosphates are at 200 ppb
- Copper is about 0.3 ppm
- Iron is at 0
Other than stabilizer, is there anything else I need to adjust? Anything I can do to correct my rough steps? And what do I need to do at closing to prevent this from happening again? Thanks for any advice, I am baffled as I take very good care of my pool, whereas neighbors only test their pool using pool test strips once a month, and don't have these issues. Thank you!