Hello! Trying to understand what could be going on with the 3 inches above my waterline. Sorry for the long and unorganized rant. I have a new (1 month with water in the pool) Latham Corinthian 16'x40' (15.4K gal) in Pearl White (Crystite Crystal). So far, love the pool and the family is really enjoying the new addition! Over the past week I have noticed a slight darkening of the shell above the water line vs a slight lightening effect of the shell under the waterline; it is consistent across the entire pool shell, not occurring in splotches. I truly can't tell if it is a lightening or darkening, but when we are splashing around, I can see a fairly distinct light/dark line at the water line. Being a new pool owner, I am quite eager to clean and sanitize, so I brush the walls near daily and also run a Dolphin Robot daily. We are planning to use SWG in the future, but PB has not installed yet, so I have been using 1 pound bags of Cal Hypo or Clorox Shock xtraBlue in the deep end, about one pound every other day. I make sure to immediately brush any granules that may settle in the deep end and run the pump for 12 hours plus run the robot to make sure the granules are quickly dissolved. We run the pump about 12-16 hours per day. Water overall looks pretty clear, no algae or major cloudiness. The first two weeks we had water in the pool, things were not balanced other than the free chlorine staying int he 1-4ppm range. When I went to balance the water the first time, I noted the pH was 6.8, TA was less than 50, CH was right around 100, and we had no CYA. Still have not added any CYA other than the small amount in the Clorox shock bags. Most recent readings are as follows: pH 7.6, CH 125, FC 1, Alk 50. Here are my questions:
1: Could the cal hypo have caused any issues? I have read cal Hypo isn't the best for fiberglass pools, but I always make sure it is dissolved well and the discoloration is not splotchy like I would expect if it was chlorine granules bleaching.
2: The two weeks, we were using 1 pound of shock per day and weren't testing the FC (pool builder said, "put in a bag a day and swim away")- Is it possible the FC was so high that it could have bleached in just 2 weeks? Again, we weren't using any CYA, so I would imagine the FC was dropping quickly as we are having many hot sunny days here in NC.
3: Would that low pH for a few weeks caused any issue?
4: Calcium levels are relatively low and it doesn't seem to be any calcium build up could occur that quickly to be the cause of lightening. Thoughts?
Thanks for any and all help!
1: Could the cal hypo have caused any issues? I have read cal Hypo isn't the best for fiberglass pools, but I always make sure it is dissolved well and the discoloration is not splotchy like I would expect if it was chlorine granules bleaching.
2: The two weeks, we were using 1 pound of shock per day and weren't testing the FC (pool builder said, "put in a bag a day and swim away")- Is it possible the FC was so high that it could have bleached in just 2 weeks? Again, we weren't using any CYA, so I would imagine the FC was dropping quickly as we are having many hot sunny days here in NC.
3: Would that low pH for a few weeks caused any issue?
4: Calcium levels are relatively low and it doesn't seem to be any calcium build up could occur that quickly to be the cause of lightening. Thoughts?
Thanks for any and all help!
