Magnesium Dosing

[cameron]

Any reason why you can't dump magnesium such as Seachems straight into the tank like in the return area? I know why you can't do alk this way, but won't mag dissolve without issue? Can doing this effect alk tank wide?

 

[xyzpdq0121]

When seachem was here speaking about Mag they said there was no reason why you could not. You would never be able to get it to disolve completly in a cup of water anyways, it would take forever. I have dumped mine in for about a year now with no problems.

 

[jmaneyapanda]

While we're on the topic, how much can you incraese the mag in a given period of time? without problems that is.

 

[glxtrix]

I've increased it 500ppm once with out issue. Granted I had a cup that had it all in there and added it over a time of maybe 5 minutes. generally I add about a 1/4 bag of epsom salts every other water change....that is if for some unknown reason my MG is below 1500.

 

[FutureInterest]

Dosing mag is fairly forgiving, its not like adding alk or ca. It's rarely the limiting component in any chemical reactions in the tank... unless you're really really low. As such, in most circumstances its not going to react to anything anyways so raise it up to where you want it.

 

[washowi]

I add 3 cups to my system every month....straight in...no waiting..

 

[dannybradley]

A super saturation will form magnesium carbonate, but if your pH is alkaline it freely dissociates. So the worst that will happen is lower KH for an unknown amount of time. My guess would be a few hours.

 

[cameron]

How about calcium? I know it can "snow" but won't it get sucked right back into the system? Dosing alk this way seems like a bad idea but i have heard people do it with success.

 

[cameron]

David, according to Seachem directions:

<span style="font-family: Arial;">Use 1 level teaspoon per 80 L (20 gallons*) twice a week. Dissolve in at least one cup of freshwater. ADVANCED: Check magnesium level, then follow dosing regimen above until magnesium is adjusted to 1200&#8211;1350 mg/L. Each dose will raise magnesium by about 5 mg/L. Size or frequency of dose can be adjusted, but do not exceed 25 mg/L per day. </span><span style="font-family: Verdana;">

</span>

So if 1 tsp does 5mg/l in 20g and you can do 25mg/L safely... 5tsp per 20g is what I get.

 

[xyzpdq0121]

Rit just dumps his pool calcium right in his tank. I did not see any snow after he did it. I use liquid calcium and dumped it right in once and did not see a problem. I just always add to my manual top off though so no reason to tempt the aquarium gods..

 

[glxtrix]

I usually dilute my drive way heat in a cup before I add it to my system....then again I usually only have to add about 30grams of the actual pellets. But I generally just dump it all right into thhe sump, never had an issue. I actually do the same with my alk. Dilute what ever is needed, generally 40grams + or - and dump into sump.

 

[dannybradley]

Calcium won't bond with magnesium. A shorter answer is that I don't think you'll hurt anything by just dumping it in your sump. You'll just offset the alk with what I would believe to be a neglible amount if you're doing a routine dose. I wouldn't follow the manufacturer dosing schedule unless you want to take 2 months to bring your Mg up 300 points.

When jacking the Mg up several hundred I usually dissolve magnesium chloride and magnesium sulfate in a 5:3 ratio into 1 gallon of water for every 100 gallons of system volume and then drip it in for about an hour. I give what's at the bottom a good stir and then dump it in the sump after the drip. I've never had an issue doing it that way.

I make a large batch of 10 cups:6 cups and use that to dose up 400-600 gallons of water for a large blast. I just cut the dose based on that ratio for smaller tanks. The smallest tank I've blasted, however, was a 150 with a 30 gallon sump dosed with 2.5:1.5. It raised the Mg by about 250. This tank had very little live rock resulting in a lower yield. More rock would have resulted in a 300-400pt boost.

 

[schwaggs]

Danny,

I read an article on Advanced Aquarist where Randy reccomended 10:1 for those people not dosing typical 2 part solutions. He indicated that 10:1 doesn't mess up the natural ionic balance and 5:3 fixes the ionic imbalance caused by 2 part formulations. Do you agree?

 

[dannybradley]

I'll have to find that article.

 

[roland jacques]

A little off topic. Who makes a mag test kit that can read over 1500 ppm preferable up to 2000?

I Think i burnt/killed a colt coral and hurt some mushrooms... by raising the mag to high very fast. ( not 100% sure it was the mag alone, I was trying to deal with very high Phosphates at the same time), I was trying the Mag sulfate raising remedy for briopsy Algae. The good news is the Briopsy took a major hit, 90% all dead or dieing.

 

[dannybradley]

I could have beent he dying algae that is causing the coral to be upset.

 

[ouling]

I'ma make this simple for everyone who don't care much about the technical stuff. I can sit here and impress you with bond angles of 10 different forms of magnesium, but that interests no body. So simply put:

Test your Magnesium, and adjust it to 1300-1500 by 300mg/l (PPM) per day. Of course you can add more but whats the rush?

Adjust your calcium and Alk afterwards by 20ppm and 1dkh respectively per day. You can make the two "balanced" if you would like.
Do not dose calcium more than your magnesium limit. (PPM of magnesium) / 3 = ( PPM Ca) your calcium saturation point

This is the safer method because I assume we all want to be a bit careful when there is $10394832 worth of livestock in the system.

Hope this helps.

P.S: Use this calculator to know the balanced point, and how much of Mg, Ca, CO3 to dose. http://home.comcast.net/~jdieck1/chemcalc.html">http://home.comcast.net/~jdieck1/chemcalc.html</a>

You dose the Mg by dumping it in a high flow area where the flakes would not fall on livestock that you care to keep alive.

 

[FutureInterest]

Good post. + rep .