Weird occurrence

[ebencic2]

Hello everyone,

I wanted to see if anyone has experienced something similar. About a month ago, while testing my water parameters, I noticed that my calcium and magnesium levels were rising, while alkalinity remained stable. I began gradually backing off my dosing, but the levels continued to increase. Eventually, both my Hanna and Red Sea calcium and magnesium tests were reading off the charts (calcium >600), so I shut off the calcium and magnesium dosing heads entirely.


For context, I’ve been using the Red Sea 4-part dosing system for the past year and have since turned off the auto-calculation feature. Since then, I’ve been struggling to get my parameters back in balance. Even though I am not dosing any calcium or magnesium, they are consistently testing around 430 ppm for calcium and 1240 ppm for magnesium.


Has anyone experienced a tank that was stable for months and then suddenly seemed to stop consuming calcium and magnesium? The only notable change around the time this started was trimming my refugium.


This is a mixed reef tank, and my current dosing is:

• Calcium: 0 mL
• Magnesium: 0 mL
• Alkalinity: 17 mL
• Trace elements: 8 mL of each bottle

I’m a bit stumped and would really appreciate any insight. I’ve been testing daily for the past 10 days—alkalinity fluctuates as expected, but calcium consistently stays around 430–450 ppm and magnesium around 1240–1260 ppm. I don't really know what to do other than an ICP test which I have ordered. It almost seems like my coral have stopped intaking calcium and magnesium. I have had 5 acros die so far and would love to prevent any further coral death.


Thanks in advance for any thoughts or suggestions.

 

[rayadog]

I wonder if there’s something unclean about testing tools

 

[ebencic2]

I wonder if there’s something unclean about testing tools

I actually thought the same thing so I made sure to clean everything within the testing kits and used two separate brands.

 

[vetteguy53081]

Hello everyone,

I wanted to see if anyone has experienced something similar. About a month ago, while testing my water parameters, I noticed that my calcium and magnesium levels were rising, while alkalinity remained stable. I began gradually backing off my dosing, but the levels continued to increase. Eventually, both my Hanna and Red Sea calcium and magnesium tests were reading off the charts (calcium >600), so I shut off the calcium and magnesium dosing heads entirely.


For context, I’ve been using the Red Sea 4-part dosing system for the past year and have since turned off the auto-calculation feature. Since then, I’ve been struggling to get my parameters back in balance. Even though I am not dosing any calcium or magnesium, they are consistently testing around 430 ppm for calcium and 1240 ppm for magnesium.


Has anyone experienced a tank that was stable for months and then suddenly seemed to stop consuming calcium and magnesium? The only notable change around the time this started was trimming my refugium.


This is a mixed reef tank, and my current dosing is:

• Calcium: 0 mL
• Magnesium: 0 mL
• Alkalinity: 17 mL
• Trace elements: 8 mL of each bottle

I’m a bit stumped and would really appreciate any insight. I’ve been testing daily for the past 10 days—alkalinity fluctuates as expected, but calcium consistently stays around 430–450 ppm and magnesium around 1240–1260 ppm. I don't really know what to do other than an ICP test which I have ordered. It almost seems like my coral have stopped intaking calcium and magnesium. I have had 5 acros die so far and would love to prevent any further coral death.


Thanks in advance for any thoughts or suggestions.

Possibly there are false readings and taking a water sample to an LFS that does not use API test would be a first step to see what readings they get and to compare with yours

 

[Delightful Reefer]

I went back and forth between Hanna and Red Sea for calcium and magnesium for months with readings way higher than Triton and ATI ICP results. Tried new testers and reagents, and finally switched to Salifert. Much more confidence in my numbers now.

Still using Hanna for alkalinity, NO₃, and PO₄ without any problems.

 

[ebencic2]

Possibly there are false readings and taking a water sample to an LFS that does not use API test would be a first step to see what readings they get and to compare with yours

I don't think its a false reading as I have used two different tests to confirm the results.

 

[ebencic2]

I don't think its a false reading as I have used two different tests to confirm the results.

But did take a sample to lfs and they also got undetectable ranges

 

[brittlestar]

What's your substrate like? I know probably nobody uses it anymore but I've read that Jaubert method tanks can naturally dissolve aragonite over time

 

[Randy Holmes-Farley]

About a month ago, while testing my water parameters, I noticed that my calcium and magnesium levels were rising, while alkalinity remained stable. I began gradually backing off my dosing, but the levels continued to increase. Eventually, both my Hanna and Red Sea calcium and magnesium tests were reading off the charts (calcium >600), so I shut off the calcium and magnesium dosing heads entirely.

No, that will not happen if alkalinity continues to be used at the same rate. I'd look for a testing issue or a pump mismatch.

I'm not sure what you are dosing, or what size tank, but unless you dosed over 28 dKh of alk during that time, you would not get that big of a drop in calcium (from >600 ppm to 400 ppm) from consumption.

 

[Randy Holmes-Farley]

What's your substrate like? I know probably nobody uses it anymore but I've read that Jaubert method tanks can naturally dissolve aragonite over time

Substrate dissolution adds both alk and calcium in a balanced fashion. :)

 

[Randy Holmes-Farley]

But did take a sample to lfs and they also got undetectable ranges

For calcium? With what kit?

Meaning they tested calcium and got over 600 ppm, and did not test further?

There is no such thing as undetectable calcium in seawater (assuming the kit is used properly and working properly). Just keep adding titrant until you get to the endpoint, and add the values together if you use more than a chart provides values for.

 

[Randy Holmes-Farley]

I actually thought the same thing so I made sure to clean everything within the testing kits and used two separate brands.

What brands?

 

[ebencic2]

No, that will not happen if alkalinity continues to be used at the same rate. I'd look for a testing issue or a pump mismatch.

I'm not sure what you are dosing, or what size tank, but unless you dosed over 28 dKh of alk during that time, you would not get that big of a drop in calcium (from >600 ppm to 400 ppm) from consumption

What brands?

Currently I have used Red Sea, Hanna, and Salifert (from lfs test) and they all read the same.

 

[ebencic2]

For calcium? With what kit?

Meaning they tested calcium and got over 600 ppm, and did not test further?

There is no such thing as undetectable calcium in seawater (assuming the kit is used properly and working properly). Just keep adding titrant until you get to the endpoint, and add the values together if you use more than a chart provides values for.

I get what you are saying my hanna checker flashed 600 and the other two tests capped out. If we assume that the tests are not the problem is there any other reason my tank would stop intaking calcium and magnesium all of the sudden like this? Take is a 75 gallon display with a 30 gallon sump. I dose Red Sea 4 part (not using the auto calculator based on calcium dosing) and have for the 6 or 7 months. The lack of consumption started around 2 months ago.

 

[ebencic2]

Hello everyone,

I wanted to see if anyone has experienced something similar. About a month ago, while testing my water parameters, I noticed that my calcium and magnesium levels were rising, while alkalinity remained stable. I began gradually backing off my dosing, but the levels continued to increase. Eventually, both my Hanna and Red Sea calcium and magnesium tests were reading off the charts (calcium >600), so I shut off the calcium and magnesium dosing heads entirely.


For context, I’ve been using the Red Sea 4-part dosing system for the past year and have since turned off the auto-calculation feature. Since then, I’ve been struggling to get my parameters back in balance. Even though I am not dosing any calcium or magnesium, they are consistently testing around 430 ppm for calcium and 1240 ppm for magnesium.


Has anyone experienced a tank that was stable for months and then suddenly seemed to stop consuming calcium and magnesium? The only notable change around the time this started was trimming my refugium.


This is a mixed reef tank, and my current dosing is:

• Calcium: 0 mL
• Magnesium: 0 mL
• Alkalinity: 17 mL
• Trace elements: 8 mL of each bottle

I’m a bit stumped and would really appreciate any insight. I’ve been testing daily for the past 10 days—alkalinity fluctuates as expected, but calcium consistently stays around 430–450 ppm and magnesium around 1240–1260 ppm. I don't really know what to do other than an ICP test which I have ordered. It almost seems like my coral have stopped intaking calcium and magnesium. I have had 5 acros die so far and would love to prevent any further coral death.


Thanks in advance for any thoughts or suggestions.

Sorry for the confusion I get the testing numbers are weird but I am wondering if there would be any other reason that my tank would stop consuming as much calcium and magnesium as it was previously. I have re-calibrated all dosing heads (forgot to mention before) so I do not believe its a dosing pump error.

 

[Randy Holmes-Farley]

Repeating:
There is no mechanism taking place that stops consumption of calcium while alkalinity is consumed.

Back to my earlier comment about tank size and product, I cannot provide a full answer without knowing how much alk you are actually dosing per day in dKH. Calcium depletion always seems far slower than alkalinity. 18-20 ppm of calcium is consumed for each 2.8 dKH of alk consumed.

But also, you do realize that this product is not designed for 1:1 dosing, right? Alk is dosed twice as much as the calcium? If you dose 1:1 based on alk, calcium will rise.

 

[LOZReefer]

Sounds silly, but have you checked Salinity? If you have, when was the last time it was calibrated?

 

[ebencic2]

Sounds silly, but have you checked Salinity? If you have, when was the last time it was calibrated?

I actually checked it yesterday and it was 1.025 but have not calibrated it in a while.

 

[ebencic2]

Repeating:
There is no mechanism taking place that stops consumption of calcium while alkalinity is consumed.

Back to my earlier comment about tank size and product, I cannot provide a full answer without knowing how much alk you are actually dosing per day in dKH. Calcium depletion always seems far slower than alkalinity. 18-20 ppm of calcium is consumed for each 2.8 dKH of alk consumed.

But also, you do realize that this product is not designed for 1:1 dosing, right? Alk is dosed twice as much as the calcium? If you dose 1:1 based on alk, calcium will rise.

Yes before this started occurring I was dosing 2:1. I am dosing 17 mL of their alk but I do not know the conversion.

 

[ReneReef]

Yes before this started occurring I was dosing 2:1. I am dosing 17 mL of their alk but I do not know the conversion.

To help you answer Randy’s questions.
- The Red Sea alk solution is 10,000 dKH.
- In a previous post I found that your tank is 75 gallons.

This means that your daily alk consumption is about 0.6 dKH, assuming the 75 gallons is roughly your net system volume.
A KH consumption of 0.6 means that you realistically can expect a daily calcium drop of about 4 mg/L.