Magnesium dosing advice

[Eoka]

I've had a lot of success with lps and sps over the past several months and I think my demand for magnesium will be greater than what my water changes provide. So I wanted to ask whats the best way to go about this. I currently have the red sea mag pro test(which is a pain to use) and some brightwell aquatics magnesion-p. My main concern is how much to start dosing.
Specs:
125g
LPS- Hammer, bubble, duncan, acan, blasto
SPS- Acro, birnest, digi, stylo
Dose 700ml of kalkwasser per day over the entire day
kh 7.2
Calc 420
Mag is maybe 1100 the red sea test kit is easy to mess up and time comsuming
Any advice would be appreciated thanks

 

[stevedola]

I would suggest a Hanna Checker Mag test kit. Then start with your baseline test.
Test daily to track how much Mag is being used daily.
You can use Chat GPT to determine the amount of the product to dose based on your tank size(volume) to get to the desired PPM. I would suggest maintaining the Magnesium at least 1300 ppm. Some will tell you more. Chat GPT will also provide the maintenance dose to keep the level of Mag at your desired PPM based on daily consumption.

 

[Eoka]

I would suggest a Hanna Checker Mag test kit. Then start with your baseline test.
Test daily to track how much Mag is being used daily.
You can use Chat GPT to determine the amount of the product to dose based on your tank size(volume) to get to the desired PPM. I would suggest maintaining the Magnesium at least 1300 ppm. Some will tell you more. Chat GPT will also provide the maintenance dose to keep the level of Mag at your desired PPM based on daily consumption.

Would the salifert magnesium test work? Also how much can you raise magnesium a day? Does it matter?

 

[stevedola]

Would the salifert magnesium test work? Also how much can you raise magnesium a day? Does it matter?

Salifert is better than redsea. I use both (hanna + salifert) to compare and confirm results against my trident.

 

[Privateye]

I've been using epsom salt (magnesium sulfate) as my magnesium supplement for the past couple of years. Seems fine so far, and my wallet feels much better! Even buying liquid supplements in 5 gallon quantities was pretty pricey by comparison.

 

[stevedola]

Magnesium sulfate is fine and has been used for decades. I would try to use lab-grade ingredients. Whether you use Mag-P from Brightwell or the bulk reef powder lab grade, it's all basically going to do the same thing.

 

[ReneReef]

I wouldn’t test for Mg. Very unreliable.
Just dose 1 ppm for every 2.8 dKH.

 

[Eoka]

I wouldn’t test for Mg.
Just dose 1 ppm for every 2.8 dKH.

Im not sure what im dkh cosumption is because I just kept increasing my kalkwasser until it stablized. How would I figure out how much Mg I need to dose if I add 700ml with 2tbsp per gallon of kalkwasser?

 

[ReneReef]

Im not sure what im dkh cosumption is because I just kept increasing my kalkwasser until it stablized. How would I figure out how much Mg I need to dose if I add 700ml with 2tbsp per gallon of kalkwasser?

Tbsp are not an exact measurement.

Every gram of calcium hydroxide “contains” 75.685 dKH.

If you measure how many grams of calcium hydroxide go into 2 tbsp, you can easily figure it out the KH of your kalkwasser and how much KH you dose.

 

[Fish Fan]

Here's Randy's "Just Say No To Magnesium Testing" thread that might help:

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

 

[Eoka]

Here's Randy's "Just Say No To Magnesium Testing" thread that might help:

Just say NO to magnesium testing: RMM is born

OK, this thread has been many years in the making, and I'm posting it here since folks in the chem forum are probably already tired of all the threads relating to problematic magnesium testing. I'm going to propose a method, let's call it the Randy Magnesium Method, or RMM for short. All good...

www.reef2reef.com

I read that but I was confused on how to figure out how much to dose. I does kalkwasser based on my alk and dont I dont measure calcium often

 

[Eoka]

I used gemini and got Mg solution is 500mL with 1tbsp of powder and dose 2.2 mL per day. Does that seem right to maintain my Mg levels based on 566.1 mg of Ca added per day?

 

[BeablossomR_]

I've had a lot of success with lps and sps over the past several months and I think my demand for magnesium will be greater than what my water changes provide. So I wanted to ask whats the best way to go about this. I currently have the red sea mag pro test(which is a pain to use) and some brightwell aquatics magnesion-p. My main concern is how much to start dosing.
Specs:
125g
LPS- Hammer, bubble, duncan, acan, blasto
SPS- Acro, birnest, digi, stylo
Dose 700ml of kalkwasser per day over the entire day
kh 7.2
Calc 420
Mag is maybe 1100 the red sea test kit is easy to mess up and time comsuming
Any advice would be appreciated thanks

Your magnesium (~1100 ppm) is low, so aim to bring it up slowly to around 1250–1350 ppm by dosing no more than about 50 ppm per day; for a 125g system this is roughly 100–150 ml/day of Brightwell Magnesion-P (follow the bottle for exact dosing), test every few days and adjust as needed without chasing exact numbers, and once you’re in range the demand will be low compared to calcium and alkalinity. If the Red Sea kit is too inconsistent, switching kits can help with accuracy.

 

[Randy Holmes-Farley Verified Community Expert]

I read that but I was confused on how to figure out how much to dose. I does kalkwasser based on my alk and dont I dont measure calcium often

We can advise on that. Much better than trying to dose based on test measurements. Use this calculator to determine the amount of calcium dosed, and then add magnesium at 1/10th of that rate.

Reef Chemistry Calculator

I DO NOT recommend dosing a massive boost based on what may well be a testing error or low salinity. You may make a fine situation into a bad one.

 

[Eoka]

We can advise on that. Much better than trying to dose based on test measurements. Use this calculator to determine the amount of calcium dosed, and then add magnesium at 1/10th of that rate.

Reef Chemistry Calculator

I DO NOT recommend dosing a massive boost based on what may well be a testing error or low salinity. You may make a fine situation into a bad one.

Yea I just want to dose my consumption rate and let my magnesium go stabalize from my monthly water changes

 

[ReneReef]

I used gemini and got Mg solution is 500mL with 1tbsp of powder and dose 2.2 mL per day. Does that seem right to maintain my Mg levels based on 566.1 mg of Ca added per day?

Impossible to calculate anything with tbsps. Therefore impossible to check Gemini.

 

[Eoka]

Impossible to calculate anything with tbsps. Therefore impossible to check Gemini.

Do I need an exact number. Its says i can weigh 7-10g that calculation is based on 9g.

 

[Eoka]

I think i'm going to just get a salifert test kit and start dosing a small amount until i'm not seeing a decrease in Mg. I did hear that the Mg test arent very reliable so I wont try to hit a certain number just stay in a healthy range

 

[Randy Holmes-Farley Verified Community Expert]

I think i'm going to just get a salifert test kit and start dosing a small amount until i'm not seeing a decrease in Mg. I did hear that the Mg test arent very reliable so I wont try to hit a certain number just stay in a healthy range

Not a good idea, IMO. Just dose. Don’t measure at all.

 

[Eoka]

Not a good idea, IMO. Just dose. Don’t measure at all.

Thats why I made this thread because I don't know how much to dose and I use kalkwasser and I dont know my daily consumptions anymore as I just increase the amount of kalkwasser added per day to meet demand of alkalinity.