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Can't help you with Eco one chems, but your problem is not algae in the lines. I would go with the mineral cartridge,chlorine and a non chlorinated shock. Add a metal gone product while filling and don't add any sanitizer for a few days in the mean time get your alk/ph in check. I wouldn't even add any calcium yet. FYI some mineral cartridges are designed to work with bromine and some with chlorine, I think the spa frog one is bromine only, maybe some others will chime in on this.
Jacuzzi Jim,So you think I should hold off on dumping for the moment? In short, here is what I have done with the spa since the beginning. Filled with our well water using a pre-filter which we presume took much of the iron out (it was trickling into the tub in the end so the pre-filter was taking stuff out). On dealers advice added stain & scale after filling then ran clean cycle. Let heat up overnight. Calcium level pre-spa purchase was 100ppm so not very hard. Alkalinity though was 400ppm+, off the test strip chart. Kept hitting it with pH down (took about 6-7 times (lost track over the days this week) only til we got alkalinity at least in high acceptable test strip range. Spa frog had bromine cart set at 4 and mineral cart set at 6 max. Bromine was negligible. So dealer said to: hit again with 2 ozs pH down, run clean cycle, wait 20 mins then hit with 6 oz calcium, wait 20 mins then add 2 oz shock (all Spa Pure products) then wait 20 mins. Did all these things then took water to dealer again that afternoon and tested. Everything improved: bromine 3.4ppm, pH 7.2ppm, hardness 140ppm and TA 157ppm. Water clear but now tinted light aqua. Took water samples today and bromine is negligible again and pH is 7.8 again. Now dealer says to dump and refill and replace bromine cart with chlorine. I'm so confused--I never dreamed owning a spa would be so complicated. We only used twice--the night the readings were good and last night. Not sure to soak tonight or dump and refill thid weekend.