need your advice on Cal. and Alk.

Discussion in 'Water Chemistry' started by Swisswiss, Dec 29, 2016.

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  1. Swisswiss

    Swisswiss Caribbean Reef Squid

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    hello folks,

    I seem to be having some trouble getting a couple of values in that "comfort zone" id like them to be in....

    now, my tank and critters are all doing well as some of you may have seen in my thread "some coral growth" so I understand if some of you will say "dont fix it if its not broken" but I would also like to better understand whats going on, so as to optimize my future dosing schedule....

    on that note, I have suspended dosing since I came back from Cuba and my sump had crashed (came back on the 22nd of Nov.), which obviously explains the drop in Cal. and Alk...

    here are some details;

    Specs:

    450l. DT with sand bed and live rock

    about 100l. bare bottom single baffle sump with skimmer
    running GAC and biopellets (recently switched to this from No3-Po4-x)

    no macro running on reverse lighting schedule....

    numbers:
    (based on most recent test, 28th of Dec. 2016 @ 08h05)

    Cal.: 371
    Alk.: 6.317
    Salinity: 1.025
    Temp. 24.9°C
    Ph. 7.93 (this usually climbs round mid day to about 8)
    Mg.: 1440
    Po4: 0.02
    No3: 0.0

    from what iv read (great article from Randy Holmes) Cal. and Alk. interact, raising one will lower the other so what do you folks suggest I do to get alk to at least 9 and Cal. between 420 and 450?

    do I need to raise them both at the same time or fix one and then work with the other?

    as always thank you for your help
     
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  3. DSC reef

    DSC reef Giant Squid

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    Depending on what your dosing now I'd raise them both slowly together. Your magnesium level will definitely support a higher alk/calcium level so that will keep an equilibrium between the two. For instance in our reef tank I keep my mag at 1460 and dose 20ml day and night of calcium and alk to keep the tank stable at 10.5 alk and 440 calcium. You can always dose more alk than calcium or vice versa but I'd start really slow and try equal amounts to see how your values rise and stay at.
     
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  4. Va Reef

    Va Reef Giant Squid

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    You could bump salinity up to 1.026, I find this facilitates raising the "big three."

    Another option would be to do water changes with salts that mix at high calcium and alkalinity levels.
     
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  5. Swisswiss

    Swisswiss Caribbean Reef Squid

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    haven't done a water change in almost a year now.... I have a bucket of redsea salt I could use, wont that throw my Mg. out though?
     
  6. DSC reef

    DSC reef Giant Squid

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    If its blue bucket red sea salt then yes, it will through off your mag but the pro has higher levels. Since you haven't done a change in a year I'd stick to dosing. I do weekly water changes and still have to dose daily. Depending on your tanks consumption water change might not do a thing.
     
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  7. Swisswiss

    Swisswiss Caribbean Reef Squid

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    right well ill keep you all posted in couple weeks see where my numbers are..... HAPPY NEW YEAR EVERYONE!!!!! much love to all my fellow reefers and your animals <3
     
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  9. DSC reef

    DSC reef Giant Squid

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    Same to you swiss!!
     
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  10. Swisswiss

    Swisswiss Caribbean Reef Squid

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    UPDATE:

    As promised here is an update....

    just finished testing my water.....

    Date:18th Jan 2017 Time:11h10
    Ca.: 539ppm (and dropping)
    Alk.: 182ppm => 10.175 dKH
    Salinity: 1.027
    Temp.: 24.5°C (its been pretty damn cold here)
    Ph.: 8.25
    Mg.: 1440ppm
    Po4: 0.00
    No3: 0.00

    so I use Red Sea foundation elements to dose....I stopped dosing Ca once I realized I over shot the target and havent dosed Mg in a long while..

    now that I have reached the target range for alk I have adjusted the quantity of Alk buffer from 70ml to 15ml/day, (I estimated my total tank volume DT+sump at 500 L. and it seems to wok well) basing myself off the back of the bottle.....this should in theory keep my alk at around 10dkh..... ill re-test in 4 days....

    now my Ca. is a little high but nothing alarming, im going to let that drop to about 480- 500 and then start dosing Ca. again at 25ml/day (again basing myself off what it says at the back of the bottle)...

    Where im confused is my Mg... I haven't dosed in well over a month and it seems to fluctuate between 1470 and 1410....how is this possible?....my Mg test is salifert while all the others are Hanna could it be the salifert test kit is inaccurate or im getting false readings??

    thank you for your insights....
    Regards
    Jeff
     
    Last edited: Jan 18, 2017
  11. Swisswiss

    Swisswiss Caribbean Reef Squid

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