Because when I was testing my water, the alkalinity was 15 every time I made more saltwater. Plus in my tank my alkalinity was always 17-18, at one time it was 15 then I checked a few days later and it was back up to 18. It was 5 coming out of my RO
unit. And I'm assuming 10 alkalinity was my instant ocean. But I tested the deionized water, now my alkalinity is 1 without salt. I've made more salt water with the tropic Marin this morning and my alkalinity is now in the 9-12 range. But in a simple version I was worried about my alkalinity and calcium because, I thought my high alkalinity would kill the fish and live rock. I did have one fish after I got my alkalinity to 15 and my nitrates and trites back to 0. It went and hid in one of my live rock and when I woke up it was dead. Then I wandered why so I checked my alkalinity and it was 18 again. So I just figured that is what had killed my bicolored angel, which was beautiful by the way.
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