Elevated Magnesium

[jdloftness]

Slowly but surely, my water parameters are getting better. My test results are as follows (tested weekly):

PH 8-8.2
Amonia 0
Nitrite 0
Nitrate 20-50 (reducing each week with use of export brick and microbacter7)
Alkalinity 8.5
Calcium 450ish
Magnesium 1480-1500
Phosphate 0.11
Temp 79
Salinity 1.207/36

I conduct a 10% weekly water change. Any thoughts off the top of your head why my magnesium is elevated week after week after week? Advice is appreciated.

 

[Greg P]

Test your new saltwater before you use it. Most likely it's elevated.
Also, drop your salinity a bit. 1.026/35 is the highest I'd recommend. This will marginally drop all your parameters.

 

[SPR1968]

What test kit are you using for magnesium?

 

[Rybren]

When you say elevated week after week, do you mean that it is rising each week or that it is remaining high?

If it is rising, then something that you are adding to your tank is causing it to rise - possibly a salt mix with high Mg, or some other additive.

If you mean that it is remaining high, then that is to be expected because so little of it is used. For every 2.8 dKH of alk consumed, only 18-20ppm of calcium is consumed and only 0-2ppm of Mg is consumed. It takes a long time before that consumption will be detected by a test kit.

 

[jdloftness]

Test your new saltwater before you use it. Most likely it's elevated.
Also, drop your salinity a bit. 1.026/35 is the highest I'd recommend. This will marginally drop all your parameters.

FYI - I tested the 5 gallons. Instead of 2 1/2 cups salt/5 gallons RODI, I only used 2 cups. My magnesium tested about 1200, which is significantly less than my main tank. Hopefully slowly reducing the salinity will also reduce my magnesium as you recommended. Thanks again.

 

[kyleinpdx]

FYI - I tested the 5 gallons. Instead of 2 1/2 cups salt/5 gallons RODI, I only used 2 cups. My magnesium tested about 1200, which is significantly less than my main tank. Hopefully slowly reducing the salinity will also reduce my magnesium as you recommended. Thanks again.

I dont know if Greg P was saying you need to lower your mag, but rather by lowering your overall salinity, magnesium will decrease; since you are putting less salt mix into the tank/diluting the magnesium you have, however you'd like to think of it.

But 1500 mag isnt anything i would worry about. LOW magnesium can cause issues with tank chemistry, but until you get into "whoops I spilled the whole bottle of kent tech m in the tank" levels of magnesium high magnesium just doesnt matter that much.

Focus on your no3 and take things slowly so you dont strip the water completely rather than worry about your mag.

 

[jdloftness]

I dont know if Greg P was saying you need to lower your mag, but rather by lowering your overall salinity, magnesium will decrease; since you are putting less salt mix into the tank/diluting the magnesium you have, however you'd like to think of it.

But 1500 mag isnt anything i would worry about. LOW magnesium can cause issues with tank chemistry, but until you get into "whoops I spilled the whole bottle of kent tech m in the tank" levels of magnesium high magnesium just doesnt matter that much.

Focus on your no3 and take things slowly so you dont strip the water completely rather than worry about your mag.

No, I don't think he was trying to tell me I needed to lower my magnesium. I think he was just suggesting how to do it. Thanks for your thoughts also. I guess I just figured if it was a lot higher than the so-called "recommended range," it must be bad. I won't stress too much about it then. I am encouraged by my SLOW reduction in no3 and have read that I need to have a little no3 and phosphate to not starve things. Again, thank you.

 

[kyleinpdx]

No, I don't think he was trying to tell me I needed to lower my magnesium. I think he was just suggesting how to do it. Thanks for your thoughts also. I guess I just figured if it was a lot higher than the so-called "recommended range," it must be bad. I won't stress too much about it then. I am encouraged by my SLOW reduction in no3 and have read that I need to have a little no3 and phosphate to not starve things. Again, thank you.

I'm sure some others will chime in, but I can tell you I've run higher mag (1600-1800) for extended periods of time, back before vibrant and the discovery of fluconazole it was believed high mag inhibited algae growth.

 

[Greg P]

...

 

[Greg P]

FYI - I tested the 5 gallons. Instead of 2 1/2 cups salt/5 gallons RODI, I only used 2 cups. My magnesium tested about 1200, which is significantly less than my main tank. Hopefully slowly reducing the salinity will also reduce my magnesium as you recommended. Thanks again.

What was the SG test with this mix?
Your Mag was 1200, but what was the SG? Did you still get 1.026?

You cannot measure your Mag unless you first measure your Sg @ 1.026

 

[Greg P]

FYI - I tested the 5 gallons. Instead of 2 1/2 cups salt/5 gallons RODI, I only used 2 cups. My magnesium tested about 1200, which is significantly less than my main tank. Hopefully slowly reducing the salinity will also reduce my magnesium as you recommended. Thanks again.

Give us more info !!
You used 2 cups in 5 gallons, but you haven't told us what final SG you achieved !!
Did you get 1.026?

Tell us what Big 3 tests you get after you mix enough salt to get 1.026, regardless of how much salt or water you use.
To clarify, when you get 1.026 water, tell us what your test results are.