First of all I would not do a 100% water change it will kill the fish
most likely. If your well or tap water has a lower pH I would start doing
10% water changes every few days to lower the pH.Have you fertilized the
lawn lately? Had any big rains which might have washed fertilizer into the
pond?

"Iris" wrote in message
...
I need some help! Pond is 5 years old.
Probably 1200 gallons.Light fish load. We have several of the original
fish & have
lost 2 or 3 over winters & 1 now & then.
But we've lost 3 in the last couple weeks.
My fav was dead today. Had water tested yesterday. They said everything
was good. Rather high PH,but not enough to klll fish. Today I had it
tested at another place. Same story. So I had water tested
at a 3rd fish store & Nitrates,Nitrites & amonia is good.Hardness is at
425. PH a whopping 9.4 & he said get fish out & change all water! Also
he said put in a cup
salt per 100 gallons We have a lot of plants & they look scorched on
edges. For the first time we have pea soup watr that won't clear with
Micro-lift. Micro lift is the only different thing we've added this
year.
Any ideas as to what we should do? Iris.