Water Treatment Advice Required

[omatai]

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

pH: 6.9

Hardness: 0ppm

Alkalinity: 159ppm

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.

[CanadianSpaTech]

Small spa... small filters usually. How often are you cleaning the filters? 

[omatai]

Have cleaned filter twice since buying it, and on second clean, we put in a brand new filter.

[CanadianSpaTech]

Recommend cleaning filters weekly. The only way to remove the organic contaminates... stuff you bring with you every time you go in..underarm deodorant shampoo if you are wearing bathing suits just rinse don't wash with regular laundry (will add to foaming). Shock weekly or as required then clean filters several hours later. What brand of spa is this? Is it an inflatable or "normal/traditional" spa?

Next time you drain use a plumbing line cleaner to disinfect the plumbing lines. Lots of stuff can be inside the plumbing from the manufacturing process. I recommend using AHH-SOME line cleaner and also their filter wash.

Rain water might be soft and require some balancing on start up but I am no chem expert so perhaps others will reply as well

[RDspaguy]

First get a good test kit. Not strips. I like taylor k2005.

Second, purge with ahhsome. Brand new spas come with all kinds of nasty in the pipes at no additional charge. They get tested at the factory then put in storage (maybe outside) then shipped on the back of a truck across country then stuck in a parking lot for a week before riding to your house. Plenty of time for a thick layer of chlorine resistant biofilm to develop. 

Third, read about chlorine and bromine maintenance, and choose your weapon. There are some good sticky threads in the spa water chemistry forum and lots more info online. Learn the basics and we are happy to answer any questions.

Sorry to hear you have no ozone. 🥺