Alkalinity & Calcium dosing and consumption

[Gungo]

When you start to think that you are doing the things right in this hobby, there's always a new thing that tells you that you're wrong. That's my case with KH and CA dosing. I have been dosing BRS two-part to my reef tank for about 5-6 months. Was a little hard to find the point and maintain my levels. I'm actually dosing daily 18ml of KH solution, and 9ml of CA solution to maintain 445 CA, 8 dKH... But someone just told me that I need to be dosing equal parts of KH, CA to my reef. This means that if I am dosing 18ml of KH, I need to be dosing 18ml of CA.. but I just don't understand why. With my current dosing, everything maintains its levels but I need to know if I am wrong! Any help????? Thank you

 

[smokin'reefer]

I am also dosing a lot more Alk than calcium. I use the Red Sea products and they actually call for more Alk.

I am probably like you and didn't follow a formula to reach my levels but tested and adjusted. I would post my dose amount but I actually dilute my solutions so it would be way over the norms.

Following along to see what others say.

 

[aeras1131]

do you mind me asking why you dilute @smokin'reefer? Does your doser dose down to one ml?

 

[aeras1131]

sorry @smokin'reefer I meant to say .1 ml

 

[RussiReef]

To keep my parameters in line I am dosing 600 mil a day Alk and 100 mil CAl .Brightwell product.

 

[Shigshwa]

I wonder if other chemical processes in the tank end up reducing alk in the tank too. My tank also consumes more alk than calcium, at about 50-60 percent more on average. Recently though, I've found that the consumption has been steadily equalizing though.

 

[Ashish Patel]

When you start to think that you are doing the things right in this hobby, there's always a new thing that tells you that you're wrong. That's my case with KH and CA dosing. I have been dosing BRS two-part to my reef tank for about 5-6 months. Was a little hard to find the point and maintain my levels. I'm actually dosing daily 18ml of KH solution, and 9ml of CA solution to maintain 445 CA, 8 dKH... But someone just told me that I need to be dosing equal parts of KH, CA to my reef. This means that if I am dosing 18ml of KH, I need to be dosing 18ml of CA.. but I just don't understand why. With my current dosing, everything maintains its levels but I need to know if I am wrong! Any help????? Thank you

I know many who dose separately and nothing wrong with it...but I think its pointless. I just spend the extra time to keep my alk stable and whatever I am dosing for alk seems to be keeping ca in balance. Calcium does not fluctuate much either so perhaps your dosing more bc its not in good ratio to your alk. No matter my best effort to get ca to 440 it stays around 415 -420 when my alk is 8.0-8.3. Perhaps it precipitate.. Now I dose 18 ml each per day brs 2 part. Definate try keeping dose same and monitor your ca. It should drop and stabilize as long as alk is stable. I look to the oceans parameter ratios for guideline. Dont chase calcium chase alk and ca will follow. Hope this helps

 

[aeras1131]

What is your live stock list?

 

[aeras1131]

what would the ppm change of Alk and Ca be if you dosed nothing for a day?

 

[aeras1131]

Do you does anything else aminos traces? Anything that would be besides the big three?

 

[aeras1131]

Do you have auto top off as well?

 

[smokin'reefer]

do you mind me asking why you dilute @smokin'reefer? Does your doser dose down to one ml?

When I started dosing I was using a medical IV pump. It used a cassette with a "delicate" diaphragm. So I diluted then and because I had it tuned in to my tank on the amount dosing I just kept this regimen.

 

[Ashish Patel]

Another point id like to mention is I find calcium much difficult to measure in regards to dosing bc tests tend to have 10+ppm error. Alk I test with hanna and cross check with red sea alk and gives me a precise value to measure consumption on brs website,

 

[smokin'reefer]

Another point id like to mention is I find calcium much difficult to measure in regards to dosing bc tests tend to have 10+ppm error. Alk I test with hanna and cross check with red sea alk and gives me a precise value to measure consumption on brs website,

Good point. I just checked my water with both Triton and ATI and calcium tested out with them at 450 whereas my Red Sea test came in at 400.

 

[Gungo]

Good point. I just checked my water with both Triton and ATI and calcium tested out with them at 450 whereas my Red Sea test came in at 400.

The thing is, most of us don't know how to test with Red Sea, we usually get the value at the first color change.. but that color usually changes back within 5 secs. To have an accurate result we need to get the color change and make sure it holds its color.

 

[Gungo]

I know many who dose separately and nothing wrong with it...but I think its pointless. I just spend the extra time to keep my alk stable and whatever I am dosing for alk seems to be keeping ca in balance. Calcium does not fluctuate much either so perhaps your dosing more bc its not in good ratio to your alk. No matter my best effort to get ca to 440 it stays around 415 -420 when my alk is 8.0-8.3. Perhaps it precipitate.. Now I dose 18 ml each per day brs 2 part. Definate try keeping dose same and monitor your ca. It should drop and stabilize as long as alk is stable. I look to the oceans parameter ratios for guideline. Dont chase calcium chase alk and ca will follow. Hope this helps

Thank you for your comment, I guess I will start dosing the same KH & CA to see how it affects those parameters!

 

[Gungo]

What is your live stock list?

Diferent types of Zoas and palys, green star polips, pulsing Xenia, Pink clavularia, Goniopora, 3 colonies of montis, birdnest and digitata frags, also some acropora frags and a few leather corals.. everything is doing great..

what would the ppm change of Alk and Ca be if you dosed nothing for a day?

CA = from 440 to 435 in 1 day if i don't dose.
KH = 8 to 7.6 if I dont dose.

Do you does anything else aminos traces? Anything that would be besides the big three?

Noup, I am just dosing KH & CA, magnesium and other traces go with my 15% water change every 15 days.

Do you have auto top off as well?

Yes

 

[Randy Holmes-Farley Verified Community Expert]

When you start to think that you are doing the things right in this hobby, there's always a new thing that tells you that you're wrong. That's my case with KH and CA dosing. I have been dosing BRS two-part to my reef tank for about 5-6 months. Was a little hard to find the point and maintain my levels. I'm actually dosing daily 18ml of KH solution, and 9ml of CA solution to maintain 445 CA, 8 dKH... But someone just told me that I need to be dosing equal parts of KH, CA to my reef. This means that if I am dosing 18ml of KH, I need to be dosing 18ml of CA.. but I just don't understand why. With my current dosing, everything maintains its levels but I need to know if I am wrong! Any help????? Thank you

You do not "need" to be dosing equal parts, but I usually recommend it until folks have a long term record of what is needed for their tank.

Note that you are almost certainly NOT consuming alkalintiy at twice the expected rate for the calcium dosed unless you are using procedures that deplete alkalinity (such as a sulfur denitrator) or add calcium (say, in tap water for top off).

What happens to many people is that water changes are messing with the ratio of the two needed. What salt mix are you using?

What size in your aquarium? I need that to know how much alk and calcium you are actually adding each day. If it is a low amount, the small effects of a variety of different things may be adding up to skew the ratio, but can also make testing less able to make fine distinctions.

Note too that when calcium carbonate is formed, the alkalinity drops much faster, on a percentage basis, than does calcium, because there is so much more calcium in seawater. That leads many folks to think they have more alk demand when, in fact, the expected calcium decline is just to small to easily detect in a day.

This article has a more extensive discussion:

When Do Calcium and Alkalinity Demand Not Exactly Balance? by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2004-12/rhf/index.htm

Finally, I find it quite notable that it is the folks with two part systems that constantly feel it important to tweak dosing levels, but folks with systems like CaCO3/CO2 reactors which has a totally fixed calcium to alkalinity dosing ratio, often claim their systems are set it and forget it, with occasional alk monitoring to see that everything is going OK.

 

[Randy Holmes-Farley Verified Community Expert]

CA = from 440 to 435 in 1 day if i don't dose.
KH = 8 to 7.6 if I dont dose.

That is close to exactly balanced demand, and is actually skewed toward extra calcium demand (but I doubt you can measure it that accurately)

0.4 dKH is associated with about a 2.7 ppm drop in calcim when forming calcium carbonate in a reef aquarium.

Your result DOES NOT reflect extra alkalinity demand.

 

[Gungo]

What salt mix are you using?

I get water directly from the sea, here in the Dominican Republic we have the national aquarium that give us water almost free.. the parameters we get directly from the sea is 7.0 KH, 420 CA, 1360 mg.

What size in your aquarium? I need that to know how much alk and calcium you are actually adding each day.

67 Gallon total volume. Im actually dosing 18ml KH, 9ml CA to maintin 8dKH, 445 CA.

Note too that when calcium carbonate is formed, the alkalinity drops much faster, on a percentage basis, than does calcium, because there is so much more calcium in seawater. That leads many folks to think they have more alk demand when, in fact, the expected calcium decline is just to small to easily detect in a day.

Thats completly new to me, It makes sense