Milwaukee ph51 tester and a newly setup tank...

[rrubberbandman]

Hey everyone,

So before I set up my tank I re-calibrated my TDS and PH pen. New tank is cycled and contains 3-4 inches of Carib sea Aragonite. (SP?) I am getting 8.4- 8.7 on my pen....it fluctuates. Should it be at a solid steady number? And is this too high? Water is crystal clear. No animals yet.....just bacteria supplement.

Thanks!

Bryan

Edited April 8, 2022 by rrubberbandman

[DaJMasta]

Steady is better, but some amount of fluctuation is normal, especially based on time of day.  If you have photosynthetic organisms in the tank (probably only algae or other microorganisms now, from your description), photosynthesis will increase pH slightly during the day, so while ideally you don't have too much of a swing between the high and low points, it's not super common for someone to have things so dialed in/automated as to be able to keep it stable within less than about half a pH.  Being on the high side is also good, most of the risks come with <7.8 pH, and you have a little more flexibility on the high size.

 

That all said, there's a reasonable chance the pH pen is reading close but not exact - most of our consumer grade test equipment is only good to within a couple tenths of a pH when in great shape and fully calibrated, so since you're relatively consistent with your readings and in the right area should be fine.  If you are able to, a multipoint calibration is better than a single point calibration (like using a 7 pH and a 10 pH buffer as references, or even including a 4 pH buffer), but otherwise a single point 7 pH or 10 pH calibration should be serviceable enough.  If you want to see if your meter may just have a little offset, you could try a chemical test kit (pH kits can be $10 or so online), or bring water into a store to have it checked against something else, just to give you some peace of mind.

[rrubberbandman]

4 minutes ago, DaJMasta said:

Steady is better, but some amount of fluctuation is normal, especially based on time of day.  If you have photosynthetic organisms in the tank (probably only algae or other microorganisms now, from your description), photosynthesis will increase pH slightly during the day, so while ideally you don't have too much of a swing between the high and low points, it's not super common for someone to have things so dialed in/automated as to be able to keep it stable within less than about half a pH.  Being on the high side is also good, most of the risks come with <7.8 pH, and you have a little more flexibility on the high size.

 

That all said, there's a reasonable chance the pH pen is reading close but not exact - most of our consumer grade test equipment is only good to within a couple tenths of a pH when in great shape and fully calibrated, so since you're relatively consistent with your readings and in the right area should be fine.  If you are able to, a multipoint calibration is better than a single point calibration (like using a 7 pH and a 10 pH buffer as references, or even including a 4 pH buffer), but otherwise a single point 7 pH or 10 pH calibration should be serviceable enough.  If you want to see if your meter may just have a little offset, you could try a chemical test kit (pH kits can be $10 or so online), or bring water into a store to have it checked against something else, just to give you some peace of mind.

THANKS!