My wife and I recently purchased a house with an inground pool. The pool was opened last week -- though not by the most helpful person. He managed to get get the filter, pump and heater up and running. Also dumped in four gallons of chlorine and left. The total volume of the pool is a bit of a mystery. As the pool is kidney shaped, and the shallow is 3.5' (supposedly) to 12.5'. My calculations, using an online calculator, came to: 30000 gallons of water.
After cleaning the pool several times -- there are some nearby trees -- we started to test the water and discovered that the chlorine level is at 10ppm and the PH at 8ppm.
The pool gets decent sun exposure, and for a while we had the pool heater + solar cover on.
Doubting my readings, I took a sample to the local pool shop. They recommended a product called: PhosFREE.
We cleaned the bottom -- again -- and added 1.5L of the product to the water. The water quickly clouded.
The next morning there was "goo" at the bottom of the pool. Not the entire bottom, but in patches. We cleaned this up. And tested the water again -- this time with a home strip kit.
My readings had not changed.
Per the bottle, I added the remaining 1.5L into the pool. 24 hours later. Some "goo". Not much. But the readings are still consistent.
I've been reading that adding muriatic acid to the pool is a means to drop the PH. Is this safe, recommended? Or am I chasing a different problem?
Advice, comments, questions, are welcome.