Low dKH - is it a problem?

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I wonder if someone know the answer.  There are so many articles but still..

I get from from reefer's experiences, different answers. But I really would like to know having low dKH is a cause of concern. I have various soft corals and just three fish 2 common clown and six strip wrasse. All other water parameters are in  ideal range except dKH just below 5.

I know the ideal dKH range is between 8-9 but I haven't seen any downside in my tank. dKH is reading 5 for almost a year now. Tank is stable, croaks are growing. Fish are healthy.

Earlier, I guess around a year from now, I tried to higher dKH but since that was showing other side effects like algae problems etc I kind of left it things on its own. I do water changes but not so frequently and I don't over feed so  0 phosphate.

I appreciate everyone has different experience. Would like to hear what you guys think of this and do you think I should increase dKH?



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Reply #1

I run my own around 9 but I also have LPS & SPS coral , I think most soft corals will tolerate lower dKh as they don't require the Mg and Ca that hard corals do . Although there probably be few that are more sensitive to the conditions like leathers .
For hard corals, low Kh limits the amount of Mg and Ca available to the coral to continue growing so can cause problems. It will also affect the amount of Ph swing in the tank once the lights are off as the CO2 rises during the night.


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Reply #3

I've been gradually dropping mine from 9 to 7 because I was getting a few burnt tips on my SPS.