I'll repeat:
Since we know very little about people coming in here, it is best, imo,
to hold firm to the advice given by the experts at AKCA/KOI USA and those
that taught the KHA course (actual Fish Vets). That mantra being: "Frequent
Partial Water Changes" of 10%/week. (Very few in here have ponds over 5,000
gallons, so I'll add YMMV, read the info.)

And since the OP, Priss, was having troubles, she should read the wise
words on the AKCA.org site. And the info site written by Norm Meck, who was
one of the instructors, his spaciality, Water Chemistry. No one has to
take my interpretation of it as fact. ~ jan

~Power to the Porg, Flow On!~