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Advice? 2 part dosing

Discussion in 'General Discussion' started by Mike, Apr 2, 2018.

  1. Mike

    Urbandale, IA
    +7 / 0 / -0
    Hey guys -

    I have a question about 2-part dosing. I have been struggling for about 2 months with 2-part dosing - trying to get my levels of alkalinity and calcium correct.

    My first question: how many mL/day do people dose? I am currently running mine at 120mL/day, which seems a bit high, doesn't it? My tank is a 125 gallon tank with a 40 gallon sump. So maybe 130 gallons of water total when taking rock/sand into account? That just seems like a lot?

    I am using the BRS 1.1 ml/minute dosers. I am dosing soda ash twice a day, once at midnight (60 mL) and once at 3am (60 mL). I am then dosing calcium at noon (60 mL) and 3pm (60 mL).

    My results so far haven't been great. My alkalinity seems to be staying in the correct range, but my calcium keeps dropping. Using the Red Sea test kits, here are my results:

    Wednesday 3/28
    Alkalinity - 8 dKH
    Calcium - 420 ppm

    Sunday 4/1
    Alkalinity: 9 dKH
    Calcium: 360 ppm

    Where should I go from here? Somebody told me at one point that you should dose the same amount of soda ash as calcium since they are supposed to balance each other out. But this doesn't appear to be the case for me?

    I tested magnesium on March 16th and it was showing 1400 ppm, so a lack of magnesium shouldn't be a problem?

    I do weekly 15-17 gallon water changes using Red Sea Pro Salt.

    My other numbers (in case they are relevant):

    SG: 1.026
    pH: 8.21
    Dissolved Oxygen: 8.2 ppm
    Temperature: 78 F
    Ammonia: 0 ppm
    Nitrite: 0 ppm
    Nitrate: 10 ppm
    Phosphate: 0.10 ppm

    My RODI water I use is measuring 0 ppm TDS.

    AM I dosing too much solutions? Should I lower the soda ash and leave calcium where it is?

    Any suggestions would be appreciated. :)
  2. blackx-runner Administrator Website Team Leadership Team GIRS Member

    Cedar Rapids, IA
    +737 / 5 / -0
    How many stony corals you have? Clams? That would help determine if that is a pretty high dose.
    What test kit are you using? I had issues with red sea mag tests always reading high. Went with salifert and they read more "normal" levels. You definitely want good quality test kits. Although if you run the tests consistently your result would be consistent even if they were wrong. So it looks like something is sucking the Ca out of there.

    Have you calibrated the dosing pumps to see if maybe they aren't actually dosing the same amount?
    It doesn't seem like you are too far off. If you can't find anything suspect I would just up the Ca a little bit. I'm sure there are a lot of tanks out there that don't end up with an exact even dose of both parts for one reason or another.
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  3. Mike

    Urbandale, IA
    +7 / 0 / -0
    I have a handful of stony corals - nothing too crazy though. And no clams. I am using the Red Sea test kits for alk/calc/mag.

    I left calcium where it is and lowered the soda ash to 80 mL/day to see if that makes a difference. Do you think that I should manually dose calcium to try to bring it back up to 420?

    I also have a couple of stony corals that are dying off and bleaching. Could the swings in alk/calc be killing them???
  4. blackx-runner Administrator Website Team Leadership Team GIRS Member

    Cedar Rapids, IA
    +737 / 5 / -0
    alk swings will definitely cause issues with corals
  5. Actuary Well-Known ReefKeeper GIRS Member

    Adel, IA
    +139 / 1 / -0
    Definitely don't feel like you need to dose equal parts of alk and calcium. I have about 400g and the tank is very lightly stocked with SPS corals. I use about 85 mL per day on soda ash and about 115 mL per day on calcium chloride. I just try to keep parameters at NSW levels and adjust my dosing accordingly.

    To me it seems like you're dosing fairly heavily given your stocking levels.. do you have coralline algae growing like crazy? A 60 ppm drop in calcium over 4 days while also dosing seems hard to believe. Can you find another calcium test kit to check against? I really like Salifert for calcium.
  6. Waterrat41 Addicted Reefer GIRS Member

    Des moines
    +120 / 0 / -0
    Definitely recheck with another kit first and check actual output rate of your pumps. My brs pumps run a pretty consistent 1.6ml/minute so you my be dosing more that you realize. As @Actuary@Actuary stated that seems a little heavy, you could be overdosing to the point of precipitation causing the rapid drops. I have a 90 display stuffed and I'm dosing about 70ml\day
  7. ShaneP Well Known Hawkfish GIRS Member

    Williamsburg, IA
    +123 / 0 / -0
    One of my dosers runs at 1.2 ml and another at 1.8 ml.

    Alk and Ca are like a seesaw. Too high of one drops the other. I was throwing things off for a little bit by dosing each the same. I had to adjust and now dose more soda ash than Ca.
  8. mattman319 SoManyTanks GIRS Member Sponsor

    Cedar Rapids, IA
    +93 / 0 / -0




    How often can u set the dosers to dose? My Kore 5th doses my soda ash every 10 minutes, my calcium chloride once an hour and my calcium nitrate once an hour. Don’t b afraid of precipitating out. Mine dose with only 5 minutes between each, twice every hour. If u r worried about rapid dispersement, add a small circulation pump to the return section like I did. Keeps stuff constantly moving. I run 4 tanks with a total of around 300 gallons and am dosing 250 ml a day of each. Hit me up if u have any more questions. Here are a few sections of the system.
  9. jeffmr4 GIRS Member

    Cedar Rapids, IA
    +31 / 0 / -0
    Last edited: Apr 10, 2018
  10. Mike

    Urbandale, IA
    +7 / 0 / -0
    Hey everybody. Thanks for the replies....

    I am still having some issues with this, but I decided to make a few changes and see what happens....

    Somebody had suggested dosing more often and in smaller amounts, and also alternating between alk/calc to prevent swings. So here is my new schedule:

    12:00am – Alk
    3:00am – Calc
    6:00am – Alk
    9:00pm – Calc
    12:00pm – Alk
    3:00pm – Calc
    6:00pm – Alk
    9:00pm – Calc

    I also noticed there was a potential problem with my calcium container not having a hole drilled into the top so the pressure inside it may have been causing it to not dispense the correct amounts.

    I have cut it down to 80 mL/day for each as well to see if perhaps I was overdosing.

    And I ordered a different brand of test strips to make sure that the results I am getting are accurate.

    Almost all of my stoney coral has died. I can't be certain if the alk/calc swings were the culprit, but that is the leading candidate right now...

    Once my new test kits get here, I am going to start testing twice daily so I can really try to hone in on what is happening...

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