I have some questions about high PH levels. The PH in our fiberglass pool always hovers around 7.8-8.0 for some reason. When we add muriatic acid to lower it, two days later it is back up to 7.8-8.0 again. We haven't been swimming in the pool much this summer so we have just been lowering the PH right before we swim in it. How long do we need to wait after adding muriatic acid before we can swim? If we aren't planning on swimming in the pool, will any harm be done to the equipment or shell of the pool if we just leave the PH at 7.8-8.0 until we are ready to swim in it?