Alkalinity & Calcium dosing and consumption

[Gungo]

Before making the water change I get the parameters to 8, and 445 with BRS calcutalor

 

[Randy Holmes-Farley]

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

Your alk dose and calculated drop exactly match, but 9 mL of the BRS two part (which is my DIY recipe #1) added to 67 gallons of water is only a 1.3 ppm calcium boost.

How did you determine what you were dosing and/or the daily change?

 

[Gungo]

Someone told me that it has to be .1 ml of CA every gallon something like that, so for 67 gallon I thought it was 7ml of CA daily. but even with that daily dose calcium keeps going down, so I increased the dose slowly until i get the point, and it was 9ml.. it keeps going down but just a little, if i test today and maybe in one month calcium will drop from 445 to 420 or so

 

[Randy Holmes-Farley]

Before making the water change I get the parameters to 8, and 445 with BRS calcutalor

Using the new salt water parameters you quote (7 dKH and 420 pppm calcium) would drop calcium more than alkalinity and would cause a slight apparent increase in demand for calcium relative to alkalinity.

If you used a balanced supplement to reach your calcium level of 445, the alk would rise to 10.9 dKH.

 

[Gungo]

Using the new salt water parameters you quote (7 dKH and 420 pppm calcium) would drop calcium more than alkalinity and would cause a slight apparent increase in demand for calcium relative to alkalinity.

If you used a balanced supplement to reach your calcium level of 445, the alk would rise to 10.9 dKH.

So, what if i don't want 10.9 dKH? I want it at 8 - 9 dkh max, to use balanced supplemet which level do calcium need to go?

 

[Randy Holmes-Farley]

So, what if i don't want 10.9 dKH? I want it at 8 - 9 dkh max, to use balanced supplemet which level do calcium need to go?

The point is, the water change with new salt water is causing an necessary imbalance in dosing. (or a necessary imbalanced dose in correcting it to match your tank)
Shown a different way, if you used a balanced supplement on the new water to get to 8 dKH, the calcium will be only 427 ppm, not your target level of 445 ppm. That's obviously not a big difference, but you will be "causing" an apparent excess demand for calcium by doing these water changes.

 

[Randy Holmes-Farley]

FWIW, this thread inspired today's Reef Chemistry Question of the Day!

https://www.reef2reef.com/threads/r...-244-imbalanced-dosing-and-salt-mixes.334684/

 

[Randy Holmes-Farley]

Two final comments,

The doses you are using for both calcium and alkalinity are very low. Meaning demand is very low, and so effects from other sorts of influences, such as accumulating nitrate (depletes alkalinity) can become more significant than usual.

There's certainly no need for you to dose anything different than you are now if you like the values your tank has, but I would note that if you dosed equal parts (18 mL) of each part for a month, even without water changes, the calcium would only be about 40 ppm higher than it is now dosing 9 mL per day. Water changes will lower that difference even more, so if you were dosing equal parts, calcium would still be fine (IMO).

 

[Merv49]

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

Looking at the BRS two part dosing videos it would seem that it is normal to dose unequal amounts. I’m about to switch to two part from kalkwasser because my Tank uses more alkalinity than calcium.

 

[Randy Holmes-Farley]

Looking at the BRS two part dosing videos it would seem that it is normal to dose unequal amounts. I’m about to switch to two part from kalkwasser because my Tank uses more alkalinity than calcium.

FWIW, they are using a recipe I invented to make their two part.

I agree the limewater (kalkwasser) has a slight imbalance toward extra calcium, but the effect is quite small. Limewater delivers 20 ppm calcium for each 1 meq/L (2.8 dKH) of alkalinity. Real demand is usually 18-20 ppm calcium for each 1 meq/L of alkalinity, and that's what balanced two part systems generally deliver. Not much difference, but it will accumulate over time.

My DIY, as sold by BRS, has a ratio of about 19.4 ppm calcium added per 1 meq/L of alkalinity if dosed in equal parts.


Why do you think you have an imbalance and why do you think limewater will solve it?

 

[Liti]

If you dose two part in unequal amounts, can you end up with an imbalance of Na+ and Cl- ions overtime and if so are there any consequences of this?

 

[aeras1131]

Do you have a Full tank shot, so we can see your livestock?

 

[Randy Holmes-Farley]

If you dose two part in unequal amounts, can you end up with an imbalance of Na+ and Cl- ions overtime and if so are there any consequences of this?

That's not really any concern, or even possible by this mechanism (I think). It is possible for chloride to rise or fall relative to sulfate (the other main negatively charged ion), and for sodium to rise or fall relative to magnesium, calcium, and potassium (the other main positive charges), but the total of positive charges must match the total of the negative charges.

More importantly, there's no long term way to boost sodium substantially by adding a buffer that I can think of, without also needing to add something with a counterion such as chloride or sulfate (like calcium chloride). You cannot create charges out of thin air, so if the bicarbonate/carbonate part of a buffer addition is used up somehow, that negative charge must either leave some other negative charge behind (what would it be?) or be taking out a positive charge somehow (such as combination of calcium (from calcium chloride) and carbonate to form neutral calcium carbonate).

 

[Liti]

That's not really any concern, or even possible by this mechanism (I think). It is possible for chloride to rise or fall relative to sulfate (the other main negatively charged ion), and for sodium to rise or fall relative to magnesium, calcium, and potassium (the other main positive charges), but the total of positive charges must match the total of the negative charges.

More importantly, there's no long term way to boost sodium substantially by adding a buffer that I can think of, without also needing to add something with a counterion such as chloride or sulfate (like calcium chloride). You cannot create charges out of thin air, so if the bicarbonate/carbonate part of a buffer addition is used up somehow, that negative charge must either leave some other negative charge behind (what would it be?) or be taking out a positive charge somehow (such as combination of calcium (from calcium chloride) and carbonate to form neutral calcium carbonate).

Thanks that makes sense. Some companies that market balling components mention that the NaCl reef salt component is to maintain other anion ratios relative Cl levels and other cation ratios relative to Na levels. From what you mentioned in the first paragraph, the dosing of NaCl free reef salt may not be necessary, if it's function is as marketed?

 

[Randy Holmes-Farley]

Thanks that makes sense. Some companies that market balling components mention that the NaCl reef salt component is to maintain other anion ratios relative Cl levels and other cation ratios relative to Na levels. From what you mentioned in the first paragraph, the dosing of NaCl free reef salt may not be necessary, if it's function is as marketed?

What they rightfully claim is that sodium and chloride do not rise relative to sulfate and other ions that are not present in sodium carbonate and calcium chloride. That is what the sodium chloride free salt that they use provides. This is the Balling concept.

A complete two part, like B-ionic, does the same thing by basically putting the components of the sodium chloride free salt mix in one or both of the two or three parts used. [emoji3]

 

[Kennedy46]

When i first started using BRS 2 part dosing i found myself chasing the calcium levels. After a few weeks i begin to notice that when i increased my alk my calcium would drop and then i would increase my calcium and my alk would drop. Now throw in a water change with a salt mix thays high in cal and alk. Dialing in dosers can be a real pain but my advice is to be patient and make small adjustments. More stable parameters is better then chasing a desired number.

 

[mps026]

I dose 2 part and have to dose twice as much alk than calc. My tank is heavily stocked-lots of sps. I agree with Randy that water changes mess with the levels. I keep my alk at 8 and the salt i use red sea pro has much higher alk levels. My tank is thriving but i am having to tweak often.

 

[aeras1131]

I dose 2 part and have to dose twice as much alk than calc. My tank is heavily stocked-lots of sps. I agree with Randy that water changes mess with the levels. I keep my alk at 8 and the salt i use red sea pro has much higher alk levels. My tank is thriving but i am having to tweak often.

Do you dose in between water changes? I'm just curious. If you do, Wouldn't the blue bucket be a better solution for you? The Alk would not yoyo around when you did your water change, and you could simply dose against consumption from your corals. If you mixed the Blue bucket at 35 ppt you would get roughly the same params for alk in your water change as your alk target param. I know everyone likes to run their tanks differently, but I would rather dose against consumption and then do water changes for my trace minerals. If I was to use Black bucket and I was targeting 8dkh. I would use the blue bucket. There should be less tweaking of params.

I am going to include two links
Red Sea Salt
https://www.redseafish.com/red-sea-salts/red-sea-salt/
Red Sea Coral Pro Salt
https://www.redseafish.com/red-sea-salts/coral-pro-salt/

Take a look at the parameters when you mix in the middle of the page for each.

 

[Neptune1707]

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.

Good to know.....I often wondered this point when testing ca with Red Sea

 

[JoeIII]

I agree the limewater (kalkwasser) has a slight imbalance toward extra calcium, but the effect is quite small. Limewater delivers 20 ppm calcium for each 1 meq/L (2.8 dKH) of alkalinity. Real demand is usually 18-20 ppm calcium for each 1 meq/L of alkalinity, and that's what balanced two part systems generally deliver. Not much difference, but it will accumulate over time.

Thank you for posting this Randy, for some reason I have never seen this information.