Mg and Alk high?

[pulpfiction]

I have no corals yet and did a 10% water change 24 hrs ago. And use Instant Ocean. I did a lot of tests and the Mag and Alk seem crazy high. And for some reason the Ca readings between test kits are totally different. Are these ranges acceptable for soft coral?

	Alk	Mg	Ca	Phosphate	KH	PH
Salifert	10.9​	1500+	230​
API			520​	0​	17.9 or less	8.2-8.4

 

[Miami Reef]

It seems like alk is reading somewhere between 10.9-17.9

I’m more inclined to believe that the salifert reading is more accurate.

I’d definitely try staying with salifert and ensuring that you are doing to test properly, because the readings you are getting is not common with that salt brand.

IO usually has calcium between 370ppm-420ppm.

Magnesium is somewhere along 1400ppm

Alkalinity is somewhere around 9-11 dkh

 

[pulpfiction]

It seems like alk is reading somewhere between 10.9-17.9

I’m more inclined to believe that the salifert reading is more accurate.

I’d definitely try staying with salifert and ensuring that you are doing to test properly, because the readings you are getting is not common with that salt brand.

IO usually has calcium between 370ppm-420ppm.

Magnesium is somewhere along 1400ppm

Alkalinity is somewhere around 9-11 dkh

Unless I'm testing them wrong? I did the alk and mg test twice and got the same results. I have no idea what Mg is because it never changes color. For the solution I made sure the liquid line was at .85 before I started dripping it into the mix. I've never dosed anything and have always used instant ocean.

 

[Randy Holmes-Farley Verified Community Expert]

Unless I'm testing them wrong? I did the alk and mg test twice and got the same results. I have no idea what Mg is because it never changes color. For the solution I made sure the liquid line was at .85 before I started dripping it into the mix. I've never dosed anything and have always used instant ocean.

It is more likely the salt mix is roughly correct than that any random high or low test result by a hobbyist is accurate. Especially when one is high (magnesium) and one is low.

I would not worry about magnesium. If you really want a value, just a second syringe of titrant to get to the color change and add the values together.

How big is the tank? Making a very small batch of seawater from a larger bucket or bag can lead to off values as the contents may settle out during shipping.

 

[pulpfiction]

It is more likely the salt mix is roughly correct than that any random high or low test result by a hobbyist is accurate. Especially when one is high (magnesium) and one is low.

I would not worry about magnesium. If you really want a value, just a second syringe of titrant to get to the color change and add the values together.

How big is the tank? Making a very small batch of seawater from a larger bucket or bag can lead to off values as the contents may settle out during shipping.

It's a 20 gallon. I don't make a lot of salt water at a time.