It would help to state your water parameters + equipment. I don't think CHI water is any harder than ours, it comes outta the same lake

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I once blamed hard water for my inability to grow Alt. Reinecki, gracilis and other "soft water plants". I think I came to realize that my co2 just wasn't high enough or some other parameter was off. I'm not saying that's the case here, but a little more background might not hurt.