Does anyone dose Magnesium via ATO water?

[ShaggyRS6]

I am wondering if anyone adds magnesium to their ATO RO water chamber? And if so is it safe to do so if you are Auto Dosing ALK?

 

[ddc0715]

No. Ato is triggered bt the need for water. And if your mg is ok and your ato adds water daily then your water parm for mg will go sky high.dosing is based on consumption

 

[ShaggyRS6]

ok I just figured if I knew my drop
Per day, putting a couple 5 ml in each day with the ATO would keep it in check somewhat

 

[Dramad1]

This is where a doser comes into play or a CA rx

 

[JimWelsh]

Yes, I used to. It worked great. I added Mg to the ATO water based on an overall average ATO demand, which didn't really change that much over the long run. Fears of off-the-charts Mg are unfounded, if you do it correctly. If in doubt, err on the low side.

 

[Randy Holmes-Farley Verified Community Expert]

As noted, it’s a fine thing to do. It’s also not needed since the mag drop is so slow, once a week manual dosing is plenty often enough for any tank.

 

[Randy Holmes-Farley Verified Community Expert]

No. Ato is triggered bt the need for water. And if your mg is ok and your ato adds water daily then your water parm for mg will go sky high.dosing is based on consumption

let’s look at some numbers.

real demand for magnesium is, typically, 0-2 ppm per day, about 1/10th of the calcium consumption.

so if you suddenly put in 10 times the usual amount of top off water, say 20% of the tank volume, you’d be in serious trouble due to the salinity drop, but not due to magnesium. Magnesium will actually fall!

here’s how.

let’s say 10x adds 20 ppm of magnesium. Not much, but wait, the salinity drop lowered magnesium by 20% of 1300, or 269 ppm. Thus the magnesium is way down, at least until all that excess water evaporates.

 

[ShaggyRS6]

Ok Randy, that makes sense! I think I am worrying about Mag too much. Weekly it never falls below 1295, I then do a water change and its back up. I think I need to worry less about mag and concentrate on keeping the ALK at a firm 8 or higher with the Auto dosing.

Thanks again Randy.

 

[ShaggyRS6]

So the best way to raise mag would be the weekly water change? And can you boost the water change magnesium ? and if so by how much?

 

[Randy Holmes-Farley Verified Community Expert]

That’s all I did, although my water changes were daily. How much water do you change each week and do you want it to balance out the same, higher, or lower than the salt mix mag level?

 

[ShaggyRS6]

Yeah I want it higher than the salt mix level , not by much , but just so it does not go below 1300. I change about 10G a week. I make the ALK the same in the mix!

now Randy, something I noticed today, since taking your advice, I have not been messing with the Mag. I noticed my Mag went up, and my Calc came down from 480 to 450.

ALK dropped from 8.05 to 7.9 so I just dosed 1ML of that.

I will set up the auto dos tomorrow , do ALK over night and calc in the day . Although I am far from understanding how all this balances out, it’s-really interesting!!

 

[jccaclimber]

I used to do that pretty regularly in a tank with no water changes. I’d be out of town for a month at a time and was dosing something like 2 dKh/day Alk (and balanced Ca) via dosing pumps, but I never set one up for the Mg. I’d remember to check the Mg about every other trip home, and it would be 100-200 PPM below my target. Rather than worry about how fast I could raise it in my limited time home I would just calculate how much was needed to bring it back up, sump that into the ATO which took 1-2 weeks to empty, and know that it would get gradually brought back up over that time frame.
I also dosed potassium like that a couple times.

For those wondering what I did for the next two weeks, my wife was willing to fill up the ATO for me as well as feed nori, but wasn't a big fan of testing and dosing.

 

[Randy Holmes-Farley Verified Community Expert]

Yeah I want it higher than the salt mix level , not by much , but just so it does not go below 1300. I change about 10G a week. I make the ALK the same in the mix!

now Randy, something I noticed today, since taking your advice, I have not been messing with the Mag. I noticed my Mag went up, and my Calc came down from 480 to 450.

ALK dropped from 8.05 to 7.9 so I just dosed 1ML of that.

I will set up the auto dos tomorrow , do ALK over night and calc in the day . Although I am far from understanding how all this balances out, it’s-really interesting!!

A mag rise on its own is either test error, or a small salinity rise.

 

[Randy Holmes-Farley Verified Community Expert]

I don’t think I see how big the tank is, but let’s do a simple example. If you change 10% weekly with a mix that is 10 ppm magnesium higher than the tank, you are adding 1 ppm per week. So if you know the weekly need, you can add that amount.

 

[Randy Holmes-Farley Verified Community Expert]

That said, what are you using for alk and calcium? That impacts what type and how much magnesium is needed.

 

[ShaggyRS6]

That said, what are you using for alk and calcium? That impacts what type and how much magnesium is needed.

Red Sea A B and C

 

[Randy Holmes-Farley Verified Community Expert]

Ok, so you have a suitable recipe already and the mag part can be put into new salt water at the same rate you’d add it to the tank. That is, if you needed to add 10 mL over the course of a week, it can just be added into the weekly water change.

 

[ShaggyRS6]

Thanks buddy. You are awesome !