Struggling to get Magnesium to raise!

[huthain]

Hello so I jave a relatively new tank almost 3 months old added fish after it was cycled and over the past 3 weeks slowly been adding some corals that honestly seem to be thriving. My corals include a duncan, frogspawn, toadstool and hammer all doing very well.
I've been trying to raise my magnesium using red sea magnesium foundation but honestly it keeps spiking up and down while mostly going down. Here are the parameter:
Im attaching the parameters plus the history of dosing and water changes and the history of calcium and magnesium, i managed to get calcium where i wanted though.

Other points to mention im using red sea salt. I also changed my rocks over a month ago as I wasnt happy with the previous ones and got the aquaforest rocks. Ive purchased 2 different salifert kits from different LFS to double check it isnt a test kit issue.

Would love to know what im doing wrong here.
I've purchased a modern reef RKS dosing but haven't started dosing yet.

 

[Miami Reef]

Test error. Magnesium depletes very slowly. About 3 dKH alkalinity consumed will only deplete 1-2 ppm Mg.

 

[huthain]

Test error. Magnesium depletes very slowly. About 3 dKH alkalinity consumed will only deplete 1-2 ppm Mg.

Ive purchased 2 seperate test kits from different vendors they give me exactly the same reading

 

[Miami Reef]

Ive purchased 2 seperate test kits from different vendors they give me exactly the same reading

Magnesium kits are inaccurate. It’s impossible for magnesium to fluctuate to this extent. It moves very slowly. The latest advice is not testing it and dosing a fixed amount based on the known consumption rate.

 

[Garf]

Ive purchased 2 seperate test kits from different vendors they give me exactly the same reading

Looks like calcium was low initially, so I'd be double checking my salinity calibration method. There's a link to Randy's DIY solution in my sig, if interested.

 

[gbroadbridge]

Hello so I jave a relatively new tank almost 3 months old added fish after it was cycled and over the past 3 weeks slowly been adding some corals that honestly seem to be thriving. My corals include a duncan, frogspawn, toadstool and hammer all doing very well.
I've been trying to raise my magnesium using red sea magnesium foundation but honestly it keeps spiking up and down while mostly going down. Here are the parameter:
Im attaching the parameters plus the history of dosing and water changes and the history of calcium and magnesium, i managed to get calcium where i wanted though.

Other points to mention im using red sea salt. I also changed my rocks over a month ago as I wasnt happy with the previous ones and got the aquaforest rocks. Ive purchased 2 different salifert kits from different LFS to double check it isnt a test kit issue.

Would love to know what im doing wrong here.
I've purchased a modern reef RKS dosing but haven't started dosing yet.

It's either test error or your salinity is incorrect.

It is impossible for Mg to fluctuate like that.

Trust us, this is a very common error.

Best advice is to not bother measuring Mg at all as there is no such thing as an accurate hobby test kit.

 

[Fish Fan]

This article from RHF may help:
https://www.reef2reef.com/threads/just-say-no-to-magnesium-testing-rmm-is-born.1017528/