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Need help with raising Magnesium

Kessil
Joined
Dec 24, 2022
Messages
223
Hello all,

Need some help on doing magnesium. My 250 gal total volume tank is low on Mag @ 1120 (Tested with Salifert). I bought some Reef Advan tage Magnesium and read the instructions. I also used the Reef Chemistry Calculator on reef2reef and it shows to add 93oz. Of Mag 1/3 to 1/2 of that amount per day over 2 days. That seems like a ton.

Here are my question if someone can help guide me I'd appreciate it. Can I add the full 93oz to my ATO since it only adds water a few times a day, but I also added Kalkwasser to my ATO...can I put both in the same thing container and how often should I readd since my add is also being auto filled from the RO tanks


If not how much would the concentrate be if I mix that amount 24oz bottle with RO water? and how many ml a day would I need to dose?

It has construction on back for adding to ATO based off of tank vovolume and how many mg/l I want to raise it, but it also mentions not to raise Mag more ththan25g/80 L per day?

So I'm just lost and if O can add to ATO would it be 1 1/4cup added to my ATO?

Thank you for the help!
 
Moderator
Joined
Jun 11, 2008
Messages
3,845
I use Randy’s 2 part. I just add it all at once using the Brs calculator. Been doing it for years. Btw. You have to add a lot to get the mag to move. There a dosing instructions on the Brs calculator website too if your worried
 
Supporting Member
Joined
Mar 12, 2016
Messages
6,298
Hello all,

Need some help on doing magnesium. My 250 gal total volume tank is low on Mag @ 1120 (Tested with Salifert). I bought some Reef Advan tage Magnesium and read the instructions. I also used the Reef Chemistry Calculator on reef2reef and it shows to add 93oz. Of Mag 1/3 to 1/2 of that amount per day over 2 days. That seems like a ton.

Here are my question if someone can help guide me I'd appreciate it. Can I add the full 93oz to my ATO since it only adds water a few times a day, but I also added Kalkwasser to my ATO...can I put both in the same thing container and how often should I readd since my add is also being auto filled from the RO tanks


If not how much would the concentrate be if I mix that amount 24oz bottle with RO water? and how many ml a day would I need to dose?

It has construction on back for adding to ATO based off of tank vovolume and how many mg/l I want to raise it, but it also mentions not to raise Mag more ththan25g/80 L per day?

So I'm just lost and if O can add to ATO would it be 1 1/4cup added to my ATO?

Thank you for the help!
What issues is your tank or coral experiencing with Mag of 1100?
 
Vice President
BOD
Joined
May 24, 2022
Messages
5,254
What's your salinity and how are you making your salt water? If you mix low due to a malfunctioning method of salinity measurement, but add back Ca and alkalinity, you'll see a low overall Mg result. Conversely if you mix improperly to like 40ppt then dilute your brine, Mg will crash out of solution and you'll end up low (happens to me occasionally).
 
Moderator
Joined
Jun 11, 2008
Messages
3,845
What's your salinity and how are you making your salt water? If you mix low due to a malfunctioning method of salinity measurement, but add back Ca and alkalinity, you'll see a low overall Mg result. Conversely if you mix improperly to like 40ppt then dilute your brine, Mg will crash out of solution and you'll end up low (happens to me occasionally).
Interesting
 
Joined
Dec 24, 2022
Messages
223
What's your salinity and how are you making your salt water? If you mix low due to a malfunctioning method of salinity measurement, but add back Ca and alkalinity, you'll see a low overall Mg result. Conversely if you mix improperly to like 40ppt then dilute your brine, Mg will crash out of solution and you'll end up low (happens to me occasionally).
Current salinity is at 1.024[. What would you do?
QUOTE="derek_SR, post: 516305, member: 17216"]
I have this question also - I'd be careful about taking a ton of action over one crummy Salifert test result. Magnesium test kits are notoriously terrible. Your Mg *could* be perfectly normal. Just sayin.
[/QUOTE]
What do you use to test for Magnesium? Hanna?
 
Joined
Dec 24, 2022
Messages
223
What issues is your tank or coral experiencing with Mag of 1100?
Some corals don't look healthy/happy. I did read somewhere here that when using Kalk in ATO the Magnesium levels should be at 1300 minimum because of lower it will cause the calcium to precipitate and calcium will not climb
 
DBTC Coordinator
BOD
Joined
Jun 27, 2022
Messages
2,338
Current salinity is at 1.024[. What would you do?
QUOTE="derek_SR, post: 516305, member: 17216"]
I have this question also - I'd be careful about taking a ton of action over one crummy Salifert test result. Magnesium test kits are notoriously terrible. Your Mg *could* be perfectly normal. Just sayin.
What do you use to test for Magnesium? Hanna?
[/QUOTE]

I don't test for magnesium, other than ICP. Never dosed it either (my tank is mostly SPS, though).

Your salinity is just kinda low!
 
Vice President
BOD
Joined
May 24, 2022
Messages
5,254
Current salinity is at 1.024[. What would you do?
QUOTE="derek_SR, post: 516305, member: 17216"]
I have this question also - I'd be careful about taking a ton of action over one crummy Salifert test result. Magnesium test kits are notoriously terrible. Your Mg *could* be perfectly normal. Just sayin.

So you would benefit from bumping your salt up to 1.026 (and confirm how you're testing with another method.) How are you testing salinity? When you mix low, you're going to end up low on all elements, and you'll over compensate for what you do dose back (Ca and Alk).

Also how do you mix your salt (method, how you add your salt, and what salt mix)?
 
Joined
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Messages
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What do you use to test for Magnesium? Hanna?

I don't test for magnesium, other than ICP. Never dosed it either (my tank is mostly SPS, though).

Your salinity is just kinda low!
[/QUOTE]
Wait 1.024 is kind of low? What should it be at?
 

JVU

Past President
BOD
Joined
Feb 12, 2017
Messages
8,318
If you bring your salinity up to target (1.024->1.026) it will raise the concentration of all major elements including your Mg about 8% or so, should resolve your “low” Mg.

Kalk in ATO is dangerous and not recommended anymore. Dosing with a dosing pump is much more reliable.
 
Joined
Dec 24, 2022
Messages
223
If you bring your salinity up to target (1.024->1.026) it will raise the concentration of all major elements including your Mg about 8% or so, should resolve your “low” Mg.

Kalk in ATO is dangerous and not recommended anymore. Dosing with a dosing pump is much more reliable.
Ok awesome working on doing that now. Luckily it's a easier fix than I thought. Thank you!
 
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