Magnesium Dosing?

reefernj77

New member
I just ordered the salifert test kit to start testing my mag. If it turns out to be low what product should i dose to raise it? Im a little skeptical about using anything homemade.
 

doTheEvolution

New member
When I checked mine it was REALLY low. I used a huge bottle of Salifert Magnesium to get it back up. "Get it back up"? Thats what she said.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
[welcome]

You can buy the DIY ingredients from at least two online companies (Bulk Reef Supply and Buckeye Field Supply) and it would be hard to go wrong doing so:

Do-It-Yourself Magnesium Supplements for the Reef Aquarium
http://reefkeeping.com/issues/2006-07/rhf/index.php


But, if you want a commercial supplement, there are many fine brands. I'd avoid Seachem as it is not ionically balanced. ESV and Kent are likely good choices. :)

This shows how much to use:

Reef chemicals calculator
http://home.comcast.net/~jdieck1/chem_calc3.html
 

reefernj77

New member
Ok I tested my mag whig came to 900. Now that's really low considering I do 5 gallon waterchanges every sat. Like clockwork but I know it's possible. I'm going to run the test again and if it comes back the same I'm going to dose with seachems reef advantage. Now on the reef calculator it says
dose 228 tsps. This seems like a bit much to me. I know to only dose a little bit like 100 ppm a day. Do you think I will need this much? I'm going to test over span of a week to see what the levels are as I add. Is this a good product?
 

reefernj77

New member
Thats what I thought randy. I've been using tro Marin pro but my last waterchanges was with reg. Tropic
Marin because I know calc is higher on the regular one. I'm using salifert to test everyting. Like I said I'm going to test again maybe I messed up. I'm also going to test some salt I mix up. Any reason you
can think of why it's
so low?
 

Randy Holmes-Farley

Reef Chemist
Premium Member
can too much mag be bad?

Yes, but how much that needs to be isn't clear. I'm sure the danger point is well above 1500 ppm, however, for most organsims in 35 ppt seawater. :)
 

Randy Holmes-Farley

Reef Chemist
Premium Member
How much titrant was left in the syringe?

Some folks end up reading the Salifert kits (calcium and alkalinity, especially) backwards, so that when they add a lot of fluid, and are down to just a little bit left, they read that as a low amount of calcium or alkalinity. Same may be true of magnesium testing.
 

reefernj77

New member
alright my magnesium is 900 i checked again. My other parameters are as follows:
cal.-380
Alk.-8.0
Ph-8.2
I bought seachem reef advantage magnesium. How much should i add at a daily dose to get it to 1300?
 

Randy Holmes-Farley

Reef Chemist
Premium Member
If you are confident it really is that low, the calculator above will show how much to dose to get a 50-100 ppm boost. Do it in increments with a day or so in between doses. It will take a large amount!
 

bertoni

Premium Member
It might drop over time. That varies from tank to tank. Testing every few months is usually enough to keep track of the situation.
 

corigan

New member
Mine drops due to weekly water changes and low mag in the new salt mix. I usually have to redose some mag right after water changes.
 

reefernj77

New member
Once my mag, alk, and cal are were I want them, should i drip kalk to keep them stable? I made a drip with a one gallon bottle and some r/o parts. My tank evaporates about a gallon a day so i figure ill use it for top off. Ill moniter ph for the first couple weeks when i start using it. Would kalk work this way?
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Depending on the demand in the tank for calcium and alkalinity, it may supply all of the calcium and alkalinity you need (it does for me), 0r it may fall short, requiring an additional method as well.

It won't supply any magnesium, so you might want to occasionally measure it to see if it is OK, but it declines quite slowly.
 
Last edited:

njfish77

New member
Ok so im going to get my mag. up, then get cal and alk. stable with 2 part, then once all those are stable start dripping kalk, ty randy for the info.
 
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