Originally Posted by TexMan7
I have a lined approx. 50,000 gallon Koi pond and show to have a ph of 9. Best way to lower the ph?

What time of day did you take the reading, and how old is the test kit? Have you checked any other water to verify if the test kit is accurate?

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).