High Ca, low kH what should I do ...

Discussion in 'Reef Chemistry' started by Vincerama2, Sep 4, 2016.

  1. Vincerama2

    Vincerama2 Evil Overlord

    ok one Ca test is off the scale, the other kit is also off scale but I could extrapolate to 640 ca.

    Alkalinity is with one test kit between 5.8 and 6.1 and with another lower rds kit shows between 5 and 6

    So with the two different brand kits, it seems somewhat accurate.

    What does this mean really?

    PH is 8.0 according to a crappy test it and my ph probe for my monitor is dried up and useless.

    I can make up some diy calc and alk with some stuff I have.

    Can I just add the alk and the Ca will drop as kH increases? The alk recipe is basically baking soda dissolved in water I think.

    My corals don't do well so I've been testing the water lately.

    Oh and Magnesium is around 920-1000 depending on if I'm color blind or not. But I thought low magnesium was only a factor if calc was too low. I have tech-m if I need to raise it.

    Thanks guys!

    My old tank had corralling everywhere and plating corals did well. Wifebane resists my attempts at growing anything but fish.

  2. Ibn

    Ibn Supporting Member

    Do a decent size water change to reset.
  3. Vincerama2

    Vincerama2 Evil Overlord

    Reading an Article by RHF in Advanced Aquarist he suggests that at a pH below 8.2 (mine is about 8.0) that one teaspoon of washing soda raised dkH by 1.7 (.6 new/L) for 50 gallons of water. Since I have a 180 with around 25 g sump I have 200 g ( but of course I have rocks and sand too).

    I'll try 4 tsp and see how that works.

    For ph 8.2 and above he says to use baking soda to get about .4 new/L increase.

    I'm baking some baking soda into washing soda now.

    FYI: baking baking soda at around 400 F for about an hour should cook out the co2 to make it washing soda. Also to make your cake rise!!

  4. Vincerama2

    Vincerama2 Evil Overlord

    Been doing that in 5 g buckets every other day for two weeks. Will continue changing water.

  5. Flagg37

    Flagg37 Colorado member

    I had the same problem but not as extreme. I had never dosed anything and was only doing WC's to keep the nitrates down. I would go 2-3 weeks sometimes between 10% WC's because the no3 was super low. Little did I know (or fully understand) that those other elements were being soaked up faster and faster as I added new corals and others were growing. The alk I was able to quickly rectify with the BRS soda ash but I'm still struggling to get and keep my magnesium above 1200. The calcium I just let naturally fall but kept an eye on it. It's been about a month now of manual dosing and my alk sits around 9.0 ca is about 450 and mg 1100.

    @Vhuang168 also turned me on to a reference solution that fauna Marin makes that you can test your test kits against. My alk tester (Hannah) tests .5 dkh more than it is. My ca test kit (api) is 30 less. And my mg kit (Red Sea) is a whopping 150 more than what it actually is.
  6. tankguy

    tankguy BOD

    My ca runs about 600 , alk 8-9 , mag 1400 -1600. Acros are loving it.
  7. Vhuang168

    Vhuang168 Supporting Member

    Becareful when trying to. Raise your Alk. Your Mg is low. If you raise your Alk too high, it will cause precipitation, driving your Alk even lower and giving your tank a snow day!

    Sent from my iPhone using Tapatalk
    Coral reefer likes this.
  8. Vincerama2

    Vincerama2 Evil Overlord

    Yeah I should have done mag first. Not a snow day but the tank got pretty cloudy. You know when you add baking soda solution to salt water it clouds quickly... My whole tank clouded. Giving it a day or two before retesting. Then will adjust may if possible and retry the alk dose if needed. Thanks for that advice.

  9. What salt are you using?
  10. Vincerama2

    Vincerama2 Evil Overlord

    I use Instant Ocean. Years ago, I tried Reef Crystals but switched back, I can't remember the exact reason, but I think it was because some things were not doing well. In any case, I've got a fair amount of it stockpiled so I'll use it up.

    Is there a better salt for reefs (as opposed to IO which I think is more for general saltwater tanks)?

    So I dosed four tablespoons of "washing soda" (baked baking soda actually), which I had pre-dissolved insome RO water. I did this on Sunday I think. Yesterday I tested alk and it showed to be higher at 8.3 dkH, which is quite the jump from 6.

    As advised, I'm not going to test for anything else or try to adjust anything until I move the magnesium up. I inherited some Tech-M so I am going to dose the tank up to around 1300 ppm. It's between 920-1000 ppm (color change test kit, so it's in that range depending on how good your color perception is!!).

    I calculated 150ml of Tech-M dosed each day for 8 days (the instructions say to dose 1mL/gallon/day until desired levels are found).
    My tank is a 180, with 29 sump, but there is a lot of rock and sand, so I'm using 150g as my water volume for dosing purposes.

  11. rygh

    rygh Supporting Member

    Note that IO is generally slightly high in Alk, low in Calcium.
    That can be a pain for keeping things balanced unless water changes are pretty uniform.
    Or unless you add Calcium while you mix the salt.

    But seems like the opposite problem than you have.

    (I use IO)
  12. Vincerama2

    Vincerama2 Evil Overlord

  13. Kmooresf

    Kmooresf Supporting Member

    The first year of my current tank, I had calcium of 600 or more. Just not enough corals to use it up for the first year. I never saw any negative affects of this, other than a couple "snow days."

    I chase Alk pretty much ALL the time. I do run a calcium reactor now, but didn't for the first year or so. I buffer with "Brightwell aquatics Alkaline8.3." I tend to under dose with this. If I want my Alk to go from 8.0 to 9.0, it might take me 3-4 days to do so. I check Alk more than anything else, simply because it has proven to be the most dynamic in the tank. I have had high calcium, and low calcium without catastrophic effects. Mag has been low and high......again, no catastrophe. HOWEVER, I have had significant coral deaths overnight from Alk dropping below 7.5 overnight.

    I have found that if I keep my Alk around 9.0-10.0, it doesn't drop as fast, so I can catch it before it hits the death mark. I have had Alk as high as 13.0 with some noticeable stress to my LPS.

    So the key (IMO), is not to let the Alk drop below 8.0. Don't worry too much about the high calcium. You just don't have enough going on to use it up. Or, you are not getting any growth at the moment (therefor, your corals are not using the calcium) because of the Alk.

    If I mess up my Alk, the corals stop growing.......If I fix it in a day or two, it will still take another week or so before they start growing again. If I can keep my Alk in the range of 8.0-11 ish.......I will get continuous growth of the SPS (provided your calcium and Mag are not low). All three need to be in range to get good growth, and any break to those three, will cause a stunt in your tank. This is not a big deal at all, as long as they aren't dying. They will start growing again as soon as you get things back in line.

    I stopped using my doser to add calcium and Alk because it was making me lazy. I wasn't keeping up with the tank, because it was on cruise control. Everything was fine.........Until it wasn't. So, I am back to manually buffering on a regular basis. It is a pain, but it is working, and I have a much better grasp on how the tank is doing day to day.

    Sorry the tank isn't cooperating, but to me, that is normal. You just have to figure out how much, and how often to make corrections. Good luck.

    Oh, and for what it's worth, I was using "Microbe lift" reef salt, until they recently sold. I started using reef crystals as a temporary fix, until the new owners put out salt. I have had great success with reef crystals, and it's so much cheaper than the other stuff, that I am gonna stick with it. On my 4th bucket I think (I do use about a bucket a month).

    Sent from my iPad using Tapatalk
  14. Vincerama2

    Vincerama2 Evil Overlord


    I think part of my problem is not enough water changes. Not frequent enough and not enough volume. I was so used to changing a 5g bucket every whenever-I-remembered on my 58g, but adding in the sump and minusing rock, for a 58g, a 5g water change is still around 10%. Now I'm doing 5G at a time on my 180g, and only occassionally, which is probably 3%. I just figured that the fish poop would have less effect in a large tank, but ignored the Ca/Alk/Mg. But the slow growth of the few corals I do have perplexed me as everything grew in the 58. I figured it was the lights (going from dual 175Mh to much sparser Kessil 250 LEDs) (I may go back to the MH) but it seems to be more a case of bad water chemistry from neglected water changes. So I'm trying to get levels to "normally accepted" levels, then do more water changes to maintain tank health.

  15. Coral reefer

    Coral reefer President

    Um yeah, 5 gal?!? That's gonna do nothing, every time. Try like 50-100 gal!
  16. Vincerama2

    Vincerama2 Evil Overlord

    Yeah, I know, I know. I'll need two brutes to change that much water. So 5G at a time, but more often, is what I'd doing.

    There is a reason I named my tank "Wifebane".
  17. Ibn

    Ibn Supporting Member

    You can still do 5G at a time, but on a daily basis instead of weekly. At that point in time, it makes sense to invest in something like a Litermeter 3 (or take a look at the newly introduced AutoAqua Smart AWC Touch).
  18. Coral reefer

    Coral reefer President

    5 gal a day will probably maintain a tank that size that is running well, but maybe not fix problems. definitely not fast anyway

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