I am new to trouble free pools, and pool ownership in general. I recently had built a 21000 gallon vinyl in-ground pool, with spill-over spa, hayward variable speed pump, and hayward aqua-rite salt water generator. The pool builder basically built the pool, and has provided no help with maintenance or balancing the water. He showed me how to switch the valves to isolate the spa or pool, and to adjust the efficiency of the salt water generator. Since the pool has been opened, about a month now, I seem to be having trouble maintaining a reasonable amount of free chlorine. I have been running the SWG at about 85-90% efficiency for 9-11 hours at max speed on the variable speed pump, and am still at the low end of free chlorine readings. My last readings just using the test strips that my pool builder provided, were about 1 ppm free chlorine, my pH is reading high/ok, my stabilizer appears be between low and ok, and my total alkalinity is ok. One concern is the pool sees sunlight from morning to night, which could be stripping away the chlorine. My first question is, is there something else I should be doing to bring up my chlorine levels? I did use the super-chlorinate button on the generator, and that momentarily brought the levels up, but they fell back again pretty rapidly. Additionally, running the generator at 85-90% to maintain chlorine levels seems like it will kill the lifespan of the cell, should I bring this up to my pool builder and ask for a larger cell?
Additionally, I just started the spa up for the first time for a party we had this weekend. I isolated the spa and heated it to about 95 degree Celcius, and it was used for about 4 hours, with anywhere from 1-5 people in at a time, as well as several kids from 3-10 years old (they were only in for about 5-10 minutes at a time as we were concerned about having young kids in a heated spa). Everyone seemed to enjoy themselves, and no one complained of itching or burning eyes or a chlorine smell. However, the next day, I started up the spa and ran it isolated without heating or anyone in the spa, and tested the water, and my chlorine reading was off the charts (greater than 20 ppm according to the test strips after being on for a little over an hour and a half. At that point I realized, that I was over chlorinating my spa (running the cell at 85% efficiency for the much smaller body of water), as it appears the pool builder put the flow monitor for the cell in the line before the valve to isolate the pool and spa. First, I feel terrible that I was overchlorinating the water with guests in the spa to such an extent during the party. My first question is, how dangerous is this situation? No one complained about itching skin/rash or burning eyes, but I am still concerned about any issues for my guests, in particular the young children that were exposed to the elevated free chlorine in the spa. Additionally, should I ask my pool builder to change the plumbing so that this situation can not arise again (the issue here is that we are hoping to keep the spa open through the winter, after closing the pool, and still need a means to sanitize the spa during the winter), or should I just always remember to manually turn down/off the salt water generator?
Thanks in advance for any help you can provide to a new pool owner.