Magnesium additives

Am I correct in saying that we can use Epson salts to increase Mg levels in our, tanks?

I did find this link that says it is possible, has/ is anyone doing this?

 

Most Mg additives are mostly magnesium choride and only a little Mag Sulphate (about 10:1).

 

Problem with Epson salts is when the magnesium gets used up you are left with the sulphate.

 

but is sulphate not already present in salt water

I forgot to add the link in my first post so here it is now:

http://ozreef.org/diy_plans/additives/magnesium.html

 

Rob has it correct. A blend of roughly 10:1 magnesium chloride to magnesium sulphate is best, purely for the reason that the chloride and sulphate ions are then balanced (i.e. added in the same ratio as they are in NSW).

Using just Epsom salts you will get an accumulation of sulphate relative to chloride, especially if you are adding relatively big amounts. As a short term measure you can use Epsom salts with no real problems.

Clinton

*EDIT* Link to Oz Reef is 100% accurate in what it says. Not often you find unbiased, accurate information like this. It is up to each individual to choose whether they think a rise in sulphate relative to chloride is significant or not really.

 

The reason I asked this question is because I need to raise my Mg from 1080 to NSW levels, now to buy enough additive is going to cost an arm and a leg, so I wanted to use Epson salts to raise it and then use normal additives to maintain it. From what I have read, and what you guys are saying this should be ok...

 

Will these low Mg levels have any adverse affects on my corals?

 

Check out this article from RHF - should tell you everything you need to know.

http://www.reefkeeping.com/issues/2006-07/rhf/index.php

A quick summary in answer to your question:

No real research doen on effects of low magnesium because this is not expected to ever be a problem in nature.

The main problems associated with low magnesim levels in reef aquaria are a difficulty in maintaining high alkalinity and calcium levels (magnesium "poisons" the crystal structure of calcium carbonate preventing abiotic precipitiation of calcium carbonate).

 

Thanks dude, I just get worried ever since my Ca KH issue which resulted in the loss of all my corals, now I am neurotic about parameters and the expiry dates on test kits

 

Using a good salt or nsw to do a few water changes is best to raise your levels, and is also more balanced than suppliments. (In my severely lacking scientific understanding I would think adding chloride and sulfate in a balanced ratio would still cause these two elements to be unbalanced {in excess} with other ions???) Typical additives only raise your Mg level by 5mg or thereabouts per dose! So you gonna need a whole lotta suppliment to raise it. Also, according to seachem, all liquid Mg additives contain ammonia, so you will have to add it slowly to give your system time to break down the ammonia!

Using the calciumreactor with aragonite as opposed to synthetic media does help to maintain MG, but I have found that it does drift slowly downwards. Adding magnesium media as per allan will definitely help quite a bit!

Why is ur Mg so low? What is the sg of your water? Are you using Kalkwasser for top ups, as this does lead to Mg depletion!

 

I am busy looking into getting a reactor, i have not had a need for one yet... Thanks for the info.

What happened a while back was my kalkstirrer decided to dump it's load into my tank over the weekend (float switch got stuck, I have taken measure to ensure this never happens again) as a result I ended up with Ca at 220 KH at 5 and Mg at 1080, I have almost fixed the Ca, the KH is at about 9 now, unfortunately this resulted in the loss of all the coral in that tank. Water changes will help but I would be required to do a huge water change to get it back up to be even close on where it should be. I actually got some dry additive (2.5kg to be precise ) so I will be going this route.

Maybe I should just fork out and get a Ca reactor and save myself all the hassles....

 

Most magnesium additives do not contain ammonia, which reefer would knowingly add a polutant! Never heard this before and sounds bizarre.

 

I have actually read of the ammonia concern before, but it seems that it was mostly over-reaction by some individuals...

 

Yes I must say this ammonia in magnesium additives sounds like an uninformed statement (or twisted half-truth) by Seachem.

Even IF say the pure powder contains eg. 10ppm ammonia, once diluted and used to raise magnesium levels, any ammonia would be undetectable (way less than 0.005ppm) and would be quickly sorted out by the bacteria in your system

 

Thats good to hear Clinton, like i said my scientific/chemical knowlege is minimal. So if you use magnesium chloride, what would you recommend magnesium can be raised by per day?

I raised mine by 50ppm in two days using magnesiumsulphate, without any adverse effects.

 

I would not raise magnesium levels by more than 100ppm per day, and preferably split up in doses over the day, not all at once. (so maybe 50ppm in the AM and another 50ppm in the PM).

 

what about setting up a drip system to dose...

 

A drip system would work just fine, but is not necessary.

You can even mix it up in your auto-top off resevoir (as long as you still try not to exceed 100ppm added per day - a bit more than this would not be too serious though, but slower is always better).

Clinton