Magnesium levels high

Vailj123 · Oct 3, 2023

I have a Fluval Evo 13.5. It’s fairly new, maybe around 6 months old. Right now it only contains live sand, live rock, I have a small refugium in the 2nd chamber and as far as livestock just two clowns, a diamond goby and small CUC with a few snails and crabs. I have been doing 25% water changes weekly because I started dosing Calcium and Alkalinity in hopes of nurturing some corraline in a bottle I added to the tank but I got the Alk and Calc out of whack so I stopped and just did frequent water changes to get everything back to normal. As of my testing today every single parameter is near perfect except my magnesium is reading 1600 on a Red Sea titration test. I don’t have any other test kits to compare with but I believe the test to be accurate because it is slowly rising after every water change. I’m using Instant Ocean Reef Crystals salt. Cannot figure out why the magnesium just continues to rise. I want to get my parameters correct as I’m still not seeing any corraline growth after a few months since adding the bottle and I’m waiting to add corals until I see some corraline (taking my time going real slow). Anyone know why my magnesium could be so high or how I can lower it? Water changes seem to be raising it.

Icryhard · Oct 3, 2023

What are you dosing in your aquarium and what does the salt contain? Salt usually has a certain parameter range on it. Being around 1600 isn't the end of the world either. Just let it come down gradually on its own. Dose some alk and calcium if you need to correct those parameters.

Vailj123 · Oct 3, 2023

Icryhard said:
What are you dosing in your aquarium and what does the salt contain? Salt usually has a certain parameter range on it. Being around 1600 isn't the end of the world either. Just let it come down gradually on its own. Dose some alk and calcium if you need to correct those parameters.

As of now I’m no longer dosing anything. I started to dose Red Sea Calcium and Alkalinity about two months ago and I wound up making the parameters worse so for the last month I’ve been doing weekly 25% water changes to correct the Calcium/Alkalinity issue I was having and that has fixed every parameter except magnesium. Since I’ve began doing water changed the magnesium has slowly increased each time. I’m using Instant Ocean Reef Crystals which looks to average around 1440 magnesium based on a chart I found in another post. I’ll attach the photo. Also while looking at the chart it looks like my Alk may be a little low compared to others. Keep in mind I have no corals using the elements right now.

Vailj123 · Oct 3, 2023

I’ve attached my current levels. You can see on the graph in the beginning where I was dosing and then when I started water changes and everything leveled out into the green and magnesium has just crept upwards since. My PH is a steady 8.2. Salinity 1.026 at 80 degrees. Ammonia/Nitrates/Nitrates all 0. Phosphate .02.

Randy Holmes-Farley · Oct 3, 2023

The Red Sea mag kit seems prone to issues, and your magnesium is likely the same as the salt mix itself, and is likely fine.

I’d focus on other things.

Vailj123 · Oct 3, 2023

Randy Holmes-Farley said:
The Red Sea mag kit seems prone to issues, and your magnesium is likely the same as the salt mix itself, and is likely fine.

I’d focus on other things.

Thanks Randy. What is the consensus “best” magnesium test kit that you are aware of?

Vailj123 · Nov 8, 2023

I never closed this thread out. I bought a different test kit. I got the Nyos Mg test kit. As of today I got a reading on the Red Sea kit of 1700 and the Nyos kit reads 1500

Randy Holmes-Farley · Nov 8, 2023

Vailj123 said:
I never closed this thread out. I bought a different test kit. I got the Nyos Mg test kit. As of today I got a reading on the Red Sea kit of 1700 and the Nyos kit reads 1500

Another nail in the coffin of the hypothesis that magnesium is worth measuring. lol

I just think it causes more trouble than it is worth.

If folks just ALWAYS added magnesium whenever they add calcium, in the ratio of 10 ppm calcium to 0.5-1 ppm magnesium, things would be better.

Think I might start a thread...

Vailj123 · Nov 8, 2023

Randy Holmes-Farley said:
Another nail in the coffin of the hypothesis that magnesium is worth measuring. lol

I just think it causes more trouble than it is worth.

If folks just ALWAYS added magnesium whenever they add calcium, in the ratio of 10 ppm calcium to 0.5-1 ppm magnesium, things would be better.

Think I might start a thread...

I don’t even supplement anymore. With this Evo 13.5 I just do weekly water changes and it replenishes everything right where it needs to be. Just can’t understand why there seems to be a steady climb. It’s not hurting anything that I’m aware of but I did add my first two corals to the tank and all other parameters have been acceptable and stable so I guess we wait and see what happens.

Randy Holmes-Farley · Nov 8, 2023

I couldn't resist:

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

Randy Holmes-Farley · Nov 8, 2023

Vailj123 said:
I don’t even supplement anymore. With this Evo 13.5 I just do weekly water changes and it replenishes everything right where it needs to be. Just can’t understand why there seems to be a steady climb. It’s not hurting anything that I’m aware of but I did add my first two corals to the tank and all other parameters have been acceptable and stable so I guess we wait and see what happens.

Try the kit on the new salt water. Unless you use a CaCO3/CO2 reactor, magnesium cannot climb without additions or a salinity increase.