Need help with Magnesium

[fisherman82]

I am having difficulties controlling/ getting my magnesium to increase in my 110 gallon tank. My current setup has a Korallin Calcium Reactor
witch keeps my calcium at a steady 460 ppm. My salt is 1.025. PH is 8.3. KH is 170. Ammonia is good. No nitrates or nitrite. I am currently using Seachem Magnesium and dose 6 teaspoons about twice a week. The salt that I use is Neomarine. The test kit that I use to test for magnesium is ELOS Magnesium test kit. I have dosed this last week twice starting with a magnesium level of 1000. After testing yesterday my magnesium is still 1000. I have performed many water changes to try to get my values up in the last month. I am going to have a friend use a different test kit to confirm results. I was just hoping to hear some suggestions on what to do? Or see if anyone knows why my magnesium is being used up so quickly?

 

[VegasRick]

How old is the tank? What brand of salt are you using? How often do you do water changes? It takes a long time to run Mg down to 1000. Makes me suspect your testing kit

 

[-Logzor]

The problem is you're not dosing enough. It takes a ton of magnesium to raise it. You need more like 6 cups, rather than 6 teaspoons, of the solution.

Use this reef chemistry calculator to figure out exactly how much you need to dose:

Reef Chemistry Calculator

 

[fisherman82]

Hi VagasRick, My tank is about a 1 1/2 years old. The brand of salt is Neomarine. Water changes are mostly once per month but since my values have been off the last couple of months I have changed twice a month on average. I had a friend test for accuracy (salifert Magnesium) and it showed that the magnesium level was 1140ppm. The test kit that I use for Magnesium is ELOS Magnesium test kit showed 950 ppm last night. So I guess it is the test kit that is off but it’s still low. Thanks for info.

 

[Young Frankenstein]

Personaly when it comes to MG testing I dont trust the test kits, I would recomend sending a water sample to a lab and I also agree that it takes a ton of MG to raise it since it also reacts with Ca

 

[Reefnjunkie]

I tried quite a few Mag supplements before trying the mag chloride from BUlk Reef Supply and it has been great. I am not familiar with the seachem mag but I would suggest giving the mag from BRS a try, I bet its less money and a maybe even a better product

 

[Young Frankenstein]

I tried quite a few Mag supplements before trying the mag chloride from BUlk Reef Supply and it has been great. I am not familiar with the seachem mag but I would suggest giving the mag from BRS a try, I bet its less money and a maybe even a better product

+1 I also use brs

 

[REEFKEEPER10]

Yeah to get mine mag from 1380 to 1420 it takes almost 500mls. That is with BRS mag supplement. From a 1000 to 1420 you are looking at about have a gallon so it would be cheaper to switch to BRS IMO.

 

[VegasRick]

Yes it take a great deal of suppliment to bring it up from 1140 to 1400. It would probably be easier to do big water changes along with adding suppliments. A 30 percent water change with hi Mg salt should take you about a third of the way to normal levels

 

[REEFKEEPER10]

I would mix a batch of sw and test the mag to see if that isn't your problem because it could have been part of the problem.

 

[DOI]

If your doing water changes and your magnesium is still at 1000, you either have a faulty kit or bad salt. Get a seachem or salifert Mg test kit and test your values again. If still the same switch salts. Instant ocean Mg values average ~1300 mg/L for me.

 

[beaslbob]

I agree that you're simply not dosing enough.

FWIW IMHO water changes will alone never maintain magnesium. Which is why we have diy two part and other dosing schemes.

To get and keep your magnesium to to say 1350 use the on line calculator and first do a one time adjustment to 1350. If you could find a source of magnesium chloride that would be the best. But you could also use epson salts as well. I bumped my 55g from 800 ppm to 1350ppm with epsom salts. and it takes a whole lot. Like 3-5 pounds or so. so a few teaspoons here and there isn't gonna make that first large adjustment.


After you do that initial adjustment I think you'll find smaller amounts every week or so will keep it there.

But that first adjustment at least to me and one other local club member was really really scary.

using the online calcualtor and bumping up a 110g from 1000ppm to 1350 ppm requires:


50 ounces of epsom salts (4 lbs 2 oz)


42.8 oz of magnesium chloride hexahydrate (mag flake)