When you think you have WH figured out, it changes.

Same here, problems with WH in the koi pond filter. I've pulled them out
and put them in some MirAcid for a week, not seeing much of an improvement.
Yet, the ones are green in the lily pond with its outrageous pH.... Which
reminds me, I need to go check to see if my water change yesterday helped
at all. ~ jan


(Do you know where your water quality is?)