David Gibson
Premium Member
I've had my 55g up since 2008, and have always maintained water parameters through water changes. I do not have a densely packed tank, or heavily dominated by demanding corals, so it's worked well enough in the past. That has changed in the recent months though. I've seen low Alk, Ca and Mg numbers, and they haven't seemed to get any better through water changes, so I decided it was time to start supplementing. On 8/30 I received my BRS 2 part starter kit, and have been documenting my progress, which I thought would be of benefit to share with others.
Much of what I know of dosing was from presentations and information that DaveJ did in Feb. 2010 (a PDF of what he presented can be found here. Everyone may have different methods, but since I'm starting out, this is the method I chose to start with.
(Throughout my testing, I've actually been using two different Alkalinity tests to cross reference. One measures in meq/L, the other dKH, so I've documented both when I've tested.)
8/30 - First, I took a baseline of water parameters: SG: 1.026, Alk: 2.5meq/L(7dKH), Ca: 460, Mg: 840
As you can see, I'm pretty far off where I want to be. My targets are Alk: 3.5meq/L(10dKH), Ca: 420, Mg: 1350.
Alkalinity and Magnesium are low, while Calcium is high. This actually isn't unusual since the low Magnesium prevents the Calcium from being properly used.
So, my first goal is to get Magnesium in line. I don't want to increase my Mg more than 100ppm per day (DaveJ recommends half that - 50ppm, but I opted to aim for 100), so I need to first determine how many days I will need to dose: Target of 1350 - current of 840 = 510 / 100 per day = just over 5 days.
To find out how much I need to dose, I used BRS's calculator they provide on their site. I have a total of 60g of water volume, including sump, and plugging in my values and selecting Recipe 1 as my supplement, the calculator says I need to dose 2467.7mL . Divided over five days, that's 493.54mL per day . That's quite a bit, and as the supplement I am using is a salt, I have to keep an eye on my salinity as well.
Round 1 of dosing
If you're not already aware, Mg will continue to increase for a day or so after you stop dosing. So, I let things sit for a night and retested everything on 9/5: SG: 1.028, Alk: 2meq/L(6dKH), Ca: 400, Mg: 1312. Much better numbers, but now having to keep a close eye on salinity. With Mg pretty close to being where I want it, the second one to bring in line is Calcium. It's not far off the mark, so I should be able to bring them up in one day's dosing, and now I start the long haul to bring Alk up.
Mg: 1350 - 1312 = 38 (under 100, so one dose) BRS calculator tells me 183.8mL of supplement
Ca: 420 - 400 = 20 (under 50, so one dose) BRS calculator tells me 122.8mL of supplement
Alk: 10dKH - 6 = 4 (only want .5 increase per day, so 8 days of dosing) BRS calculator tells me 171.4mL / 8 = 21.425mL per day.
Round 2 of dosing
As you can see, the numbers aren't changing much. It's being used up as fast as I'm adding it. So, at this point I tell myself to not get discouraged or do anything drastic, and just continue testing and dosing.
New baseline (9/13): SG: 1.028, pH: 8.5, Alk: 3meq/L(7dKH), Ca: 420, Mg: 1437
Other than high pH from the alk dosing, everything is looking better. I will correct the salinity during my next water change, which is being postponed to prevent the numbers from getting skewed in the middle of a round of dosing.
Alk: 10 - 7 = 3 / .5 = 6 days
Calculator: 128.5mL / 6 days = 21.4 mL per day
Round 3 of dosing
So, I have continued to dose 20mL of Alkalinity per day. pH has been more stable around 8.3 (dropping to 8.1 at night).
Baseline on 9/21: SG: 1.028, pH: 8.3, Alk: 3.0meq/L(7dKH), Ca: 400, Mg: 1400
I would welcome any suggestions, but at this time, my plan is to just continue dosing 20mL nightly until I see the numbers come up more. My main objection to increasing the dosage is that I'm pretty certain it will also increase pH as well. I think I'm dosing about as much as my tank can process and keep pH stable.
Much of what I know of dosing was from presentations and information that DaveJ did in Feb. 2010 (a PDF of what he presented can be found here. Everyone may have different methods, but since I'm starting out, this is the method I chose to start with.
(Throughout my testing, I've actually been using two different Alkalinity tests to cross reference. One measures in meq/L, the other dKH, so I've documented both when I've tested.)
8/30 - First, I took a baseline of water parameters: SG: 1.026, Alk: 2.5meq/L(7dKH), Ca: 460, Mg: 840
As you can see, I'm pretty far off where I want to be. My targets are Alk: 3.5meq/L(10dKH), Ca: 420, Mg: 1350.
Alkalinity and Magnesium are low, while Calcium is high. This actually isn't unusual since the low Magnesium prevents the Calcium from being properly used.
So, my first goal is to get Magnesium in line. I don't want to increase my Mg more than 100ppm per day (DaveJ recommends half that - 50ppm, but I opted to aim for 100), so I need to first determine how many days I will need to dose: Target of 1350 - current of 840 = 510 / 100 per day = just over 5 days.
To find out how much I need to dose, I used BRS's calculator they provide on their site. I have a total of 60g of water volume, including sump, and plugging in my values and selecting Recipe 1 as my supplement, the calculator says I need to dose 2467.7mL . Divided over five days, that's 493.54mL per day . That's quite a bit, and as the supplement I am using is a salt, I have to keep an eye on my salinity as well.
Round 1 of dosing
- Day 1 (8/30): dosed 490mL
- Day 2 (8/31): Mg: [1060], SG: 1.026 - that's a much bigger jump than I expected, so I backed off a lot - dosed 300mL
- Day 3 (9/1): Mg: 1140, SG: 1.026 - dosed 300mL
- Day 4 (9/2): Mg: 1200, SG: 1.027 - dosage increased again now that the increase is inside 100 again - dosed 400mL
- Day 5 (9/3): Mg: 1213, SG: 1.027 - dosed 400mL
If you're not already aware, Mg will continue to increase for a day or so after you stop dosing. So, I let things sit for a night and retested everything on 9/5: SG: 1.028, Alk: 2meq/L(6dKH), Ca: 400, Mg: 1312. Much better numbers, but now having to keep a close eye on salinity. With Mg pretty close to being where I want it, the second one to bring in line is Calcium. It's not far off the mark, so I should be able to bring them up in one day's dosing, and now I start the long haul to bring Alk up.
Mg: 1350 - 1312 = 38 (under 100, so one dose) BRS calculator tells me 183.8mL of supplement
Ca: 420 - 400 = 20 (under 50, so one dose) BRS calculator tells me 122.8mL of supplement
Alk: 10dKH - 6 = 4 (only want .5 increase per day, so 8 days of dosing) BRS calculator tells me 171.4mL / 8 = 21.425mL per day.
Round 2 of dosing
- Day 1 (9/5): Mg: dosed 185mL, Ca: dosed 120mL, Alk: dosed 20mL (each dose was done a good two hours apart, with Alk done after lights out)
- Day 2 (9/6): Mg: 1312 (dosed another 180mL), Alk: 2.5meq/L(7dKH) dosed 20mL
- Day 3 (9/7): Alk: 2.5meq/L(7dKH) dosed 20mL
- Day 4 (9/8): Alk: 2.5meq/L(7dKH) dosed 20mL
- Day 5 (9/9): Alk: 2.5meq/L(7dKH) dosed 22mL
- Day 6 (9/10): Alk: 3meq/L(7dKH) dosed 22mL - tested pH as well: 8.17
- Day 7 (9/11): Alk: 2.5meq/L(7dKH), pH: 8.45 dosed 20mL
- Day 8 (9/12): Alk: 3meq/L(7dKH) dosed 20mL
As you can see, the numbers aren't changing much. It's being used up as fast as I'm adding it. So, at this point I tell myself to not get discouraged or do anything drastic, and just continue testing and dosing.
New baseline (9/13): SG: 1.028, pH: 8.5, Alk: 3meq/L(7dKH), Ca: 420, Mg: 1437
Other than high pH from the alk dosing, everything is looking better. I will correct the salinity during my next water change, which is being postponed to prevent the numbers from getting skewed in the middle of a round of dosing.
Alk: 10 - 7 = 3 / .5 = 6 days
Calculator: 128.5mL / 6 days = 21.4 mL per day
Round 3 of dosing
- Day 1 (9/13): Alk: dosed 20mL
- Day 2 (9/14): pH: 8.5 - I opted not to dose this day due to high pH
- Day 3 (9/15): pH: 8.4 - dosed 20mL (I thought I tested this day, but it's not in my tank journal)
- Day 4 (9/16): pH: 8.37 - Alk: 3.5meq/L(7dKH) dosed 20mL
- Day 5 (9/17): pH: 8.1 Alk: 3.5meq/L(7dKH) dosed 20mL
- Day 6 (9/18): pH: 8.42 Alk: 3meq/L(7dKH) dosed 20mL
So, I have continued to dose 20mL of Alkalinity per day. pH has been more stable around 8.3 (dropping to 8.1 at night).
Baseline on 9/21: SG: 1.028, pH: 8.3, Alk: 3.0meq/L(7dKH), Ca: 400, Mg: 1400
I would welcome any suggestions, but at this time, my plan is to just continue dosing 20mL nightly until I see the numbers come up more. My main objection to increasing the dosage is that I'm pretty certain it will also increase pH as well. I think I'm dosing about as much as my tank can process and keep pH stable.