We've had a small spa (900 litre) for about 5 weeks. We filled it with collected rainwater off a relatively new & clean roof (<6months old), and was told to treat it initially with 3 teaspoons of pH/alkalinity up and 3 teaspoons of chlorine granules, then a teaspoon or two of chlorine thereafter after each use. The pool has a silver-ion cartridge but no ozonator. A couple of weeks in, the pool quickly developed a slightly green tinge, got very foamy, and I upped the chlorine dose. If I measure the chlorine with a test strip an hour after putting it in, the strip says the chlorine level is excessive. If I measure it a day after, it says there is essentially no chlorine present. We use the spa regularly, but even when we don't, the chlorine level plummets, and the foaminess increases. The tinge now is less green than a little cloudy. It feels like there is a dead animal or something in the plumbing. I'm suspicious that this is not a new pool, but some reject that someone else has returned to the manufacturer a time or two - it feels beyond normal expectations to me.
I shocked the spa with an MPS shock the other day, and then the readings went completely nuts. So I had the water tested. The results were:
Free Chlorine: 0.62ppm
Combined Chlorine: 0.61ppm
Cyanuric Acid 126ppm
I'm shocked at these results occurring within 5 weeks. We're in a drought with water restrictions, so I'm reluctant to dump the water and start again. Should I be treating the water? Should I be taking it back to the manufacturer? I'm too new to this to know what the right thing to do is.