Unequal Dosing Question

JasonPG

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I think I'm really getting a feel for the dosing and it's impact on my tank but there is one thing I'm still a little hung up on.

Randy's Recipe calls for equal parts of Calcium and Alkalinity and urges us to only dose in equal parts. He says minor corrections may be necessary but to resist the temptation to dose in unequal parts.

Well after several months of dosing I'm quite confident in saying that my tank consumes calcium faster than the alkalinity portion.

At 0.3 ml/gal of the Alkalinity solution I observe my Alkalinity slowly rise by 0.15 DKH per day. And it's pretty dang consistent.

At 0.3 ml/gal of the Calcium solution I observe my Calclium slowly drop by about 2.5 PPM per day. Again, very consistent.

I'd like to start leveling off the Alkalinity now that my tank is hitting 8.2 PH at 10.4 DKH and 420 PPM.

According to my data, I think the tank wants about .2 ml/gal of Alkalinity and .5 ml/gal of Calcium. Is it ok to dose in uneven portions like this?
 

revhtree

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I think I'm really getting a feel for the dosing and it's impact on my tank but there is one thing I'm still a little hung up on.

Randy's Recipe calls for equal parts of Calcium and Alkalinity and urges us to only dose in equal parts. He says minor corrections may be necessary but to resist the temptation to dose in unequal parts.

Well after several months of dosing I'm quite confident in saying that my tank consumes calcium faster than the alkalinity portion.

At 0.3 ml/gal of the Alkalinity solution I observe my Alkalinity slowly rise by 0.15 DKH per day. And it's pretty dang consistent.

At 0.3 ml/gal of the Calcium solution I observe my Calclium slowly drop by about 2.5 PPM per day. Again, very consistent.

I'd like to start leveling off the Alkalinity now that my tank is hitting 8.2 PH at 10.4 DKH and 420 PPM.

According to my data, I think the tank wants about .2 ml/gal of Alkalinity and .5 ml/gal of Calcium. Is it ok to dose in uneven portions like this?

I was just feeling the same thing about my tank yesterday! My ALK is now staying consistent but my calcium is continuing to drop. I noticed my tester monti cap fading very badly is what tipped me off.
 

jwshiver

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What is your Magnesium level? How fast does your tank consume Magnesium? It might use it quicker than you think. After several weeks of playing around with my Magnesium I am dosing 10 ml per day of BRS Magnesium Mix.
 
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Randy Holmes-Farley

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The main reason for needed imbalanced dosing is water changes with a salt mix that does not match the tank. IO, for example, typically depletes calcium relative to alkalintiy, so you'd need a bit more calcium to offset this.

In any case, if you are careful about it, a fixed imbalance in dosing is fine.

It is folks jiggering the relative doses every couple of days that is, IMO, the problem. Kits just cannot catch the minor differences day to day.
 
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JasonPG

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What is your Magnesium level? How fast does your tank consume Magnesium? It might use it quicker than you think. After several weeks of playing around with my Magnesium I am dosing 10 ml per day of BRS Magnesium Mix.

My magnesium had dropped a little more than I had expected this month. I usually take it to around 1400 and let it drift down and make a monthly adjustment with the BRS Mix. It was at 1240.
 
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The main reason for needed imbalanced dosing is water changes with a salt mix that does not match the tank. IO, for example, typically depletes calcium relative to alkalintiy, so you'd need a bit more calcium to offset this.

In any case, if you are careful about it, a fixed imbalance in dosing is fine.

It is folks jiggering the relative doses every couple of days that is, IMO, the problem. Kits just cannot catch the minor differences day to day.

Thanks for the prompt response, Randy.

I needed to bring my magnesium up a little so I'm going to continue with the equal dosing for at least another couple of weeks while I monitor the impact that has. But it's good to know I can tweek it to match my own tank's needs.
 
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JasonPG

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DO you dose the magnesium part per the directions and still see a drop, or you don't dose any until a test says you need it?
For the last few months when I've exhausted parts A and B, I test the magnesium and use BRS's calculator (I went with BRS for the magnesium component) and dose the specific amount to take me back to about 1400.
 

Randy Holmes-Farley

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For the last few months when I've exhausted parts A and B, I test the magnesium and use BRS's calculator (I went with BRS for the magnesium component) and dose the specific amount to take me back to about 1400.

That's an OK plan, but my recommendation is to dose the recommended amount all along, regardless of magnesium kit results. It does more than maintain magnesium. It also keeps the chloride/sulfate balanced properly. :)
 
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JasonPG

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What is your Magnesium level? How fast does your tank consume Magnesium? It might use it quicker than you think. After several weeks of playing around with my Magnesium I am dosing 10 ml per day of BRS Magnesium Mix.

So I'm doing the math and if I go the uneven route on my system I'd be exhausting my Part A on day 50 and Part B on day 63. That equates to a daily dosing of the magnesium somewhere between 9.6-12 ml. I think 10 ml a day sounds like a great place to start!
 

revhtree

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So I'm doing the math and if I go the uneven route on my system I'd be exhausting my Part A on day 50 and Part B on day 63. That equates to a daily dosing of the magnesium somewhere between 9.6-12 ml. I think 10 ml a day sounds like a great place to start!

How are you going to dose your Mag daily? Auto or manual?
 

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Tagging along, as I've always just kept magnesium at a good level and dosed after water changes at best, and usually just once I have to refill my 1 gallon calcium and alkalinity solutions.
 

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I've been struggling with this same issue. I've read a lot about it and have had a lot of great comments from others about it, but the numbers I get don't match what I keep hearing. I have a heavy SPS tank and use Instant Ocean Reef Crystals and my Alk dosing is considerably higher (over twice as much per day) than my calcium dosing. I tried matching the two amounts for a few days and my calcium shot way up. I tried dosing less alk and sure enough my values droped way below where I want them. In just a couple of days it was 150ppm vs the 180 ppm I had before. With stability being so important, I was afraid I was going to start killing off corals. I went back to the daily does that keeps each value where I want it. Everything in the tank looks happy and the numbers test properly. I've calibrated my test kits and believe the results I'm seeing.

However, my sandbed is clumping up in some places, and I think the extra alk is going towards that. I dose magnesium by the gallon when I use up a gallon of Alk and it seems to keep the mag value where I want it. I'm not sure what the answer is.
 

Ocelaris

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I was in somewhat of the same boat a few weeks ago, and I cut off dosing for 2 days, and started back from the reccomended starting point (I think brs has the ratio on their videos on dosing). I started dosing again with the pumps and raised the levels slowly, never changing the dosers more frequently than 3 days. I did add calcium or alkalinity (baking soda solution) to get my levels even and to where I wanted them, and just kept raising my auto dosing amounts till I wasn't dropping anymore.

If I tried to raise just one (alk) my calcium would drop, so I've stopped trying to raise the alkalinity past 9.1 as increasing both doesn't seem to have a long term increase in alkalinity, but my calcium keeps rising.

I was precipitating quite a bit bit before, and it can become a run away process trying to get it right. So once I've found stability within reason I'm leaving well enough alone.
 

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If you're mixing up your own 2-part, make sure you're accurately measuring per the recipe.
 

Randy Holmes-Farley

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I've been struggling with this same issue. I've read a lot about it and have had a lot of great comments from others about it, but the numbers I get don't match what I keep hearing. I have a heavy SPS tank and use Instant Ocean Reef Crystals and my Alk dosing is considerably higher (over twice as much per day) than my calcium dosing. I tried matching the two amounts for a few days and my calcium shot way up. I tried dosing less alk and sure enough my values droped way below where I want them. In just a couple of days it was 150ppm vs the 180 ppm I had before. With stability being so important, I was afraid I was going to start killing off corals. I went back to the daily does that keeps each value where I want it. Everything in the tank looks happy and the numbers test properly. I've calibrated my test kits and believe the results I'm seeing.

However, my sandbed is clumping up in some places, and I think the extra alk is going towards that. I dose magnesium by the gallon when I use up a gallon of Alk and it seems to keep the mag value where I want it. I'm not sure what the answer is.


I'm not sure what the issue is, but calcium shouldn't go way up in a few days anyway. Perhaps that is just hyperbole.

Most likely, the two part you are using isn't exactly balanced, or somehow was mixed wrong. What brand?
 

Monkeytank

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Randy, for over a year and a half I was using your Number 1 recipe for both alk and calcium until my PH started rising too much a few months ago when I removed a rock wall and replaced some sand. I got concerned about it going above 8.5, so just about a month ago I started using the Number 2 for alk, and have been using the same recipe 1 calcium mix, as I had so much more of it left. I have always needed more alk than calcium since I set up the tank over two years ago. I mix 6 gallons when I make a batch. I'm at 6,700' elevation. I'm not sure if that might have anything to do with it. I noticed mixing the cooked baking soda I had a hard time getting the recommended amount to dissolve fully even when heating the water and using a drill and paint stirrer over and over again. With the unbaked version it mixes well at the recommended amount.

The calcium went from 430 to 550 in a few days, but the amount of clacium dosing was tripled to match the alk and went from 300ml per day to 900 ml per day. That's right 900ml of alk part 2 per day is what I'm dosing for 600 gallons total. Seems ridiculously high. To keep the calcium from rising I lowered it back to 300 ml per day. PH goes between 8.38 to 8.5 daily. I'm going to recalibrate my PH probe to see if it is off. I have used calibration fluid and two different reagents for the Alk to test my Hanna checker. I haven't calibrated my Calcium Hanna checker.
 

Randy Holmes-Farley

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Actually, that's quite a small dose of my recipe #2, if that's what you mean.

600 mL per day in 600 gallons only adds 5 ppm of calcium. A rise much faster is testing error.
 

Monkeytank

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Actually, that's quite a small dose of my recipe #2, if that's what you mean.

600 mL per day in 600 gallons only adds 5 ppm of calcium. A rise much faster is testing error.

Now I'm not sure what to think about any of my dosing.

I've been using the reef calculator at http://reef.diesyst.com/flashcalc/flashcalc.html. According to it, to move calcium from 430 to 550 with recipe 1 would take 7369 ml for 600 gallons.
 
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