low alk (6dkh) and calcium 400ppm ???????

[littlesilvermax]

Originally Posted by Aleks

Ahh, ok so what I was thinking was correct, that a balanced increase in both is what will correct the problem... up it to ~450 calcium and around 9 dkh....

That is about right. I personally only target about 430 for calcium and between 7 & 10 for dkh. (always nice to have it higher then NSW in case something happens)

Don't forget that unless magnesium id where it should be (above 1300 ppm) you won't get those numbers, as magnesium helps hold calcium in suspension.