Who Doses Magnesium

[Michael_Price]

Does anyone here Dose Mag? I do not.. Nor do I even have the test kit.. When I asked my LFS they said on small tanks with weekly water changes you don't really need to worry about it. Is this true?? I have a Doser with 4 pumps, I am currently Dosing Ca, Alk, and NoPox. So I have a 4th pump thats not even running and don't mind adding it. Thoughts?

 

Do you dose this? Is it as necessary to monitor as Alk and Ca? Or is it pretty self sufficient?

 

Thanks in Advance!

 

30 Gallon tank, 5 Gallon Sump, Weekly 5 Gallon Water Changes.

[flatlandreefer]

Mg levels are critical when it comes to balancing Ca and Alk. I dose my freshly mixed salt water since instant ocean is low in mg. Mg will deplete over time and will take quite a bit of an additive to get it back up to acceptable levels. Basically if you are testing alk and Ca you need to me testing mg

[BulkRate]

Macroalgae will make keeping it (and by extension alkalinity & calcium) an interesting struggle. Chinese proverb sense of the word. At least when 50% of the tanks' bioload is seaweed.

 

I have to add 4-5ml of Ions (aqua vitro's Mg additive) every week or levels will bottom out and then it's just a matter of time before my blastomussas and euphylia become sad & melted. 9 gallon tank...it may be folk with somewhat larger don't have this issue.

[Michael_Price]

Macroalgae will make keeping it (and by extension alkalinity & calcium) an interesting struggle. Chinese proverb sense of the word. At least when 50% of the tanks' bioload is seaweed.

 

I have to add 4-5ml of Ions (aqua vitro's Mg additive) every week or levels will bottom out and then it's just a matter of time before my blastomussas and euphylia become sad & melted. 9 gallon tank...it may be folk with somewhat larger don't have this issue.

Thanks for that information guys. Guess I need to get a mag test kit and additive.

[Clown79]

I have a 10g and 15g and dose mag.

 

Waterchanges only work if your tank doesn't use any mag up between waterchanges.

 

If your tank uses up mag you have to do multiple waterchanges a week to replenish it or dose according to tanks usage.

[TheKahnasaur]

I dose Mg in my 15 gal. It needs about 3mls a week. If your Alk and Ca levels are stable, chances are your Mg is at good levels as it keeps them in balance. If you're adding more vol of one than the other, then your Mg is probably low.

[-E-]

My tank is 6 months old. Every month brings new algae but so far I've lost only one snail. So I think my water is safe but my calcium is usually low. I've been dosing tech m (for the algae) and the calcium seems to rise on its own. 

 

I have absolutely nothing to contribute for this thread. Just letting you know you're not the only one confused about salt brands, dosing, and element exchange.

[CronicReefer]

I have a refugium full of algae so I dose magnesium regularly. I also like to keep magnesium around 1350 as this makes calcium much more stable and thr salt mix I use mixes around 1280.

[HarryPotter]

I squirt in some B Ionic Mg occasionally 

[chipmunkofdoom2]

I test and dose magnesium to every water change. I then test my tank monthly and adjust if necessary. Part of that is because I use plain Instant Ocean and the Mg levels are very low, and part of that is because testing and dosing Mg just doesn't take that much time and isn't that difficult.

 

All of the salt mixes I have used have been deficient in magnesium. I used TMPR for my first bucket of salt, for example, and the magnesium always measured slightly below levels found in natural seawater:

 

 

Fairly consistent results, but just a tad low. Instant Ocean is even worse, usually measuring in between 900 and 1000 ppm. The amount of calcium and carbonate that can be dissolved into a seawater solution is directly proportional to the level of magnesium: without magnesium, calcium and carbonate molecules will find themselves in the solution and precipitate out, making both levels difficult to maintain. NSW levels of magnesium are fine if all you want to run is NSW levels of calcium and carbonate (alkalinity) (about 420 ppm and 7dKh respectively). However, if you want levels higher than NSW, you're going to need to maintain higher magnesium concentrations.

 

The only way to know if you need to dose magnesium is to test it. I think a good starting point would be to pick up a reliable Mg test kit from Salifert or Red Sea and go from there.

 

I break out this soapbox almost every post now, but I don't personally see what the big deal is with testing. We as reefers will spend hundreds to thousands of dollars on a reef setup, but spending 20 minutes per water change testing and dosing the big three (ca/alk/mg) is just too much time to invest. Doesn't make sense to me. But then again, not much in this world does.

[RayWhisperer]

I used oceanic(I know everybody hates it. It worked great for me.) and the ESV 4 part salt. Mag levels were always fine. I rarely dosed mag. If I tested cal and alk and they were low. I tested mag. If they were fine, I wouldn't bother.

[do not smoke the reef(er)]

about to start dosing 2 part in my 20 g

 

i do a weekly water change of about 15% and i wanted to know how to compensate for this. I figured if i do not lower my Ca and Alk a little bit before the water change the levels would spike? Does the same happen with mag? 

[RayWhisperer]

I'm not sure I'm following your logic..... the only way any element will spike from a water change is if the new water is more "saturated" than the water you just removed. 

 

As an example.

tank sits at

ca 420

alk 8 dkh

mg 1350

 

3 gallons of new water somehow mixed up to be

ca 600 

alk 15 dkh

mg 1900

 

that might put you tank around

ca 520 ish

alk 10 to 12  dkh ish

mg 1600 ish

[flatlandreefer]

6 hours ago, do not smoke the reef(er) said:

about to start dosing 2 part in my 20 g

 

i do a weekly water change of about 15% and i wanted to know how to compensate for this. I figured if i do not lower my Ca and Alk a little bit before the water change the levels would spike? Does the same happen with mag? 

 

You ca and alk will spike somewhat if your fresh salt water has higher ca and alk than your levels you are targeting while dosing. To get rid of the spike you should dose to maintain new salt levels, if your freshly mixed salt mixes to 9 dkh dose to maintain 9dkh. Mg is not as prone to spiking as it takes a lot longer to be depleted and a lot of salt mixes are low in mag, instant ocean. I add 6 oz of mag solution every time I mix up a batch of salt water so my magnesium levels don't fall every time I do a water change because instant ocean mixes to a low level of mg, around 1100. 

[do not smoke the reef(er)]

15 hours ago, flatlandreefer said:

 

You ca and alk will spike somewhat if your fresh salt water has higher ca and alk than your levels you are targeting while dosing. To get rid of the spike you should dose to maintain new salt levels, if your freshly mixed salt mixes to 9 dkh dose to maintain 9dkh. Mg is not as prone to spiking as it takes a lot longer to be depleted and a lot of salt mixes are low in mag, instant ocean. I add 6 oz of mag solution every time I mix up a batch of salt water so my magnesium levels don't fall every time I do a water change because instant ocean mixes to a low level of mg, around 1100. 

 

16 hours ago, RayWhisperer said:

I'm not sure I'm following your logic..... the only way any element will spike from a water change is if the new water is more "saturated" than the water you just removed. 

 

As an example.

tank sits at

ca 420

alk 8 dkh

mg 1350

 

3 gallons of new water somehow mixed up to be

ca 600 

alk 15 dkh

mg 1900

 

that might put you tank around

ca 520 ish

alk 10 to 12  dkh ish

mg 1600 ish

 

 

Thank you guys for the help!