*Help* Alk is dropping less the calcium? (Dosing Help)

tjsweldind94

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75 Gallon water volume with sump, Not seeing any precipitation or anything my alk dropped from 9.1dkh to 8.6dkh in 3 days and the brs calculator recommends dosing 21.4ml of brs liquid soda ash to get back to 9.1dkh which would be 7.13ml per day to keep it stable, but on the other hand I’m thrown of is my calcium dropped very little also 454ppm to 446ppm and brs calculator recommends dosing 61.4ml of liquid calcium chloride to get back to 454ppm and 20.46ml per day to keep it stable this just seems like I’d be dosing to much calcium compared to alkalinity daily, I thought they were supposed to be dosed almost equally?
 

Tamberav

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You dose equally. The test kit for calcium isn’t very accurate anyways.

I don’t even test my calcium regularly. It’s not that important since I dose based off alk and it always stays acceptable range.
 

Tamberav

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@Tamberav Okay so would a safe bet be to dose the same as my alk and then make minor adjustments from there?

just dose off alk and shouldn’t be any reason to adjust since alk and ca are taking up in a certain ratio.

There is a lot of posts I am sure from randy about it.
 
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tjsweldind94

tjsweldind94

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just dose off alk and shouldn’t be any reason to adjust since alk and ca are taking up in a certain ratio.

There is a lot of posts I am sure from randy about it.
Okay thank you do you thing that but dosing off af alk my calcium levels will fall or rise to the sweet spot and remain in that general range?
 
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tjsweldind94

tjsweldind94

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The dosage will change over time anyways as the consumption of your reef inhabitants require more and more of both…
I understand what I’m asking is if I raise my alkalinity to 9dkh and keep it ther by dosing the 7.1ml a day and the same dose of 7.1ml calcium will calcium just fall down from say 454 to 430 and stay there and then as the tank grows I raise them both the same to compensate for alk loss to find the new stable spot
 

Tamberav

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I understand what I’m asking is if I raise my alkalinity to 9dkh and keep it ther by dosing the 7.1ml a day and the same dose of 7.1ml calcium will calcium just fall down from say 454 to 430 and stay there and then as the tank grows I raise them both the same to compensate for alk loss to find the new stable spot

yea you raise based on alk.
 

arking_mark

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75 Gallon water volume with sump, Not seeing any precipitation or anything my alk dropped from 9.1dkh to 8.6dkh in 3 days and the brs calculator recommends dosing 21.4ml of brs liquid soda ash to get back to 9.1dkh which would be 7.13ml per day to keep it stable, but on the other hand I’m thrown of is my calcium dropped very little also 454ppm to 446ppm and brs calculator recommends dosing 61.4ml of liquid calcium chloride to get back to 454ppm and 20.46ml per day to keep it stable this just seems like I’d be dosing to much calcium compared to alkalinity daily, I thought they were supposed to be dosed almost equally?

Ca and Alk are almost consumed equally in our aquariums. Roughly 7ppm Ca per 1 dKH. Hence your perceived 9ppm Ca drop was larger than your 0.5dKH drop.

However, our hobby test kits are at best +/- 15ppm for Ca and many much worse. So you could have a 2dKH change in Alk and not see a change in Ca. Or in your case, see a large change in Ca, with smaller changes in Alk.
 

Randy Holmes-Farley

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As noted above, your result is not low calcium depletion. It is exactly normal within test kit uncertainty.

Stick to equal parts dosing.

Calcium moves up and down too slowly to gauge dosing based of it. Only adjust the calcium dosing if calcium is already getting too high or too low.
 
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tjsweldind94

tjsweldind94

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As noted above, your result is not low calcium depletion. It is exactly normal within test kit uncertainty.

Stick to equal parts dosing.

Calcium moves up and down too slowly to gauge dosing based of it. Only adjust the calcium dosing if calcium is already getting too high or too low.
Okay awesome I appreciate you guys helping me get a better understanding most of the information I got was so misleading! Thank you @Tamberav @arking_mark & @Randy Holmes-Farley and Happy Reefing
 

Randy Holmes-Farley

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My consumption was never equal in my 75. Always dosed much more alk than ca to keep things stable.

How much alk and calcium per day were you dosing to keep things stable?

Some folks misunderstand what "equal" actually means,. Not all additive systems are even designed for 1:1 dosing, so those will never be equal volumes.

The reasons why a tank may deviate from the normal 18-20 ppm of calcium demand per 1 meq/l (2.8 dKH) of alkalinity demand are discussed in this article:

When Do Calcium and Alkalinity Demand Not Exactly Balance? by Randy Holmes-Farley - Reefkeeping.com

Water changes and nitrate rising or falling are the main ones for real imbalances.
 

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