There should be a LOT number on the bottle. From API:
"Each reagent bottle has a Lot # printed
on the bottle. The last four digits are the month and year of
manufacture. Example: Lot # 28A0102. This is a pH
in January of 2002. "
What time of day are you testing your pH?
How long have the lights been on before you test?
What salt mix are you using?
If you mix a batch to an SG
of 1.025 and let it aerate overnight with a powerhead and heater what are the pH, Alk
, etc. readings the next day?
Are you using RODI
or tap water to mix?
The reason I ask that pH will be highest just before ligths out and lowest just before lights on.
's should maintain all the parameters including Alkalinity and pH.
I like the Salifert line of test kits for Ca
, Nitritate, and Alk