ZOMG my pH is 8.65!! (Solved:bad calibration solution)

Discussion in 'Water Chemistry' started by exactlyobp, Apr 12, 2012.

to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

  1. RickM

    RickM Astrea Snail

    Joined:
    Apr 5, 2012
    Messages:
    67
    Location:
    Las Vegas
    Why should his Mg be so high? Where are you getting those numbers?

    You aren't adding anything to supplement ca/alk? Water changes alone are maintaining those levels? Seems like if you had any skeletal growth or any coraline algae growth you would need to supplement with more than weekly water changes.

    It's not uncommon in the wild for the pH on reefs to peak around 8.6.
     
  2. Click Here!

  3. Vinnyboombatz

    Vinnyboombatz Giant Squid

    Joined:
    Oct 24, 2010
    Messages:
    6,344
    Location:
    Dunnellon, Florida
    Mag. value should be roughly three times Calcium level.;)
     
    1 person likes this.
  4. exactlyobp

    exactlyobp Giant Squid

    Joined:
    Jan 24, 2011
    Messages:
    3,984
    Location:
    Cedar City UT
    I seem to go back to Reefkeeping site whenever I have questions/issues/problems about my tank. I will read once again, see if it applies to my case and let you know.

    Thanks Steve so far. I appreciate it!

    No Im not dosing at all, none of those 2 part, limewater, kalkwasser or anything. I have only 13 kinds of SPS frags, along with small LPSs in the tank at the moment. They are all happy and growing/encrusting. Coralline algae is growing as well, but no dosing needed. Im using straight up RODI for ATO as well. I use Coralife salt mix.

    Do you have a reference source on this?
     
  5. steve wright

    steve wright Super Moderator Staff Member

    Joined:
    Feb 17, 2009
    Messages:
    11,283
    Location:
    shenzhen Guangdong PRC
    Your welcome - check out the other link on accuracy of calibration fluids also , as many a person has made a change reacting to a test kit or probe reading when in reality it was not needed

    Steve
     
  6. RickM

    RickM Astrea Snail

    Joined:
    Apr 5, 2012
    Messages:
    67
    Location:
    Las Vegas
    Where are you getting that from?
     
  7. exactlyobp

    exactlyobp Giant Squid

    Joined:
    Jan 24, 2011
    Messages:
    3,984
    Location:
    Cedar City UT
    Now the pH is showing 8.44.
    Last two days chart:
    [​IMG]
    You can see when I calibrated the probe where its off the chart.

    A couple minutes ago, the RB LEDs came on, see what happens!
     
  8. Click Here!

  9. steve wright

    steve wright Super Moderator Staff Member

    Joined:
    Feb 17, 2009
    Messages:
    11,283
    Location:
    shenzhen Guangdong PRC
  10. RickM

    RickM Astrea Snail

    Joined:
    Apr 5, 2012
    Messages:
    67
    Location:
    Las Vegas
    I still think there might be some reading issues but ..Were you using some time of buffer in the past? Many aquariums with a lot of coraline and sps use as much as 2 dkh per day. I just find it unusual that you have coraline growth and don't have to supplement at all? How often do you take alk reads?

    I could find some references if you like, shouldn't be hard with all the ocean acidification studies. I do remember a reef off Japan which had pH peak reads of 8.8. So while not the normal it also isn't that unusual to find high pH. A discussion I had with Calfo he said he was taking peak readings of 8.6 on reef crests in many areas.

    A quick search found
    The basics of acidication: baseline variability of pH on Australian coral reefs
    and from it
    Differences were found in pH between inshore
    and offshore waters along Ningaloo Reef (means 8.45, 8.53,
    respectively). Replicate assessments here ranged from 8.22
    to 8.64.
     
  11. RickM

    RickM Astrea Snail

    Joined:
    Apr 5, 2012
    Messages:
    67
    Location:
    Las Vegas
  12. steve wright

    steve wright Super Moderator Staff Member

    Joined:
    Feb 17, 2009
    Messages:
    11,283
    Location:
    shenzhen Guangdong PRC
    Welcome Rick
    it goes on to say that in nature Magnesium ions are just over 3 x the volume in weight of calcium ions
    hence its generally regarded that you Mag level is 3 x your calcium level
    it does not have to be exact and it can be far from exact , many salt mixes these days have elevated calcium levels but do not have 3 x the mag levels
    it is very possible to have a tank with 500ppm calcium and less than 1500 magnesium
    but in principle a mag level 3 x calc level would be a close ratio to nature

    although my preference would be a more natural calcium level rather than increasing mag to be 3 x an elevated calcium level