ph calibration?

[bawla47]

i bought some calibration solution from coralife, and tried to calibrate a new probe i bought.

i was able to get 4 from the ph4 solution, but when i went up to the 7.00 solution, i could only get a reading of 6.90 during calibration.

is it the solution im using and i should switch to pinpoint maybe?



it was a brand new probe, does it need to be "broken in" for a few days or something?


anyhow i really need the help, i apreciate it.

thanks
Jaymie

 

[bawla47]

ttt

 

[Billybeau1]

What brand probe ?

 

[szwab]

what kind of calibration fluid? the one time use packets or larger bottles?
I have heard the one time packets are more accurate for whatever reason

 

[MBX5]

As far as I know you should use 7 and 10 for saltwater. It shouldn't matter what reading you get when you calibrate. You put it in and adjust it to read the right # then move to the next and do the same. So say you put it in 7 and you get 7.06 adjust to be 7.0 then put it in 10 and now you get 10.1 adjust that to read 10 that should get the average and should now be set right. Again it may depend on the type of monitor.

 

[bawla47]

i have a neptune aquacontroller, i dont think i can manually adjust it.


im using coralife calibration solution, in a bottle liquid form. ,

 

[szwab]

the bottle type have a really short shelf life after they are opened. I found out (just recently) that it is best to stick with the single use foil packets.
I would bet that is where the problem is. Neptune recomends using 7 and 10 solutions. here are the directions from the manual.
with the aquacontroller you should be able to off set the reading to match the calibration fluid. The following procedure outlines the steps necessary:
1. Go to the Setup: pH Setup menu. Enable or disable temperature
compensation depending upon your requirements.
2. Select the pH Calibrate menu.
3. Use the Up and Down buttons to select the lowest valued
calibration solution. In order for the calibration procedure to
work correctly the lowest valued calibration solution must be used
first.
4. Place the pH probe into lowest valued calibration solution. Wait
for the numbers on the bottom of the LCD screen to stop
changing. It does not matter what value is displayed only that it is
not changing. When the display stops changing press the select
button.
5. Rinse the probe in room temperature tap water.
6. Use the Up and Down buttons to select the high valued
calibration solution. Press the select button when the correct
value is displayed.
7. Place the pH probe into high valued calibration solution. Wait for
the numbers on the bottom of the LCD screen to stop changing.
When the display stops changing press the select button.
8. The pH probe should now be properly calibrat

 

[MBX5]

^^^ just as above ^^^ you just hit set when the number stops changing. It will automatically average it for you after you do the 2 test. I also use a neptune and the second test is never 10 but after the 2 calibrations it works out.