Hanna tester - am I missing something?
Just calibrated a new Hanna tester with standard solutions. Everything went smoothly.
So, I go and test the tanks which has not been done in ages. These tanks have only emerged Crypts! There are about 170 plants most doing very well. The starting water was 4 parts RO / 1 part tap water pH 7.8
To my surprise, 4 of the tanks tested pH ~ 8.3. That included a 125 gal blackwater set up.
The TDS was ~ 1150 ppm!!! The blackwater tank showed 550 ppm.
When the tester was put into RO water, it tested pH of 6.85 with 1 ppm.
I won't go into the rest of the details, but something seems radically wrong. Could the tester be defective?
Any ideas? Thanks in advance.