Implications of low magnesium?

[phishcrazee]

I finally got a magnesium test and see what I suspected is true....... I have very low magnesium levels, about 200ppm to be exact. I know low levels interfere with growth and keep alkalinity levels low, but what else? Anybody know what other problems low magnesium might cause? What was your solution if you had low magnesium; just add more?

 

[Atticus]

Low mg can cause PH and Ca/ALk instability. It will also decrease growth of coral and coralline algae.

 

[kau_cinta_ku]

dang how do you get levels of 200ppm. I would think that even with regular water changes it would keep your mag levels at around 1000 even using a salt mix with low levels.

 

[matt the fiddler]

I would double check that test kit before dosing..... especially if you ahve done a water change in the last 4 months.

That seems realllllllllllllly low-

Matt

 

[Dave Dunbar]

I agree Thats way to low. what salt are you using? Make sure of the reading and maybe double check with another test kit if possible. What test kit are you using?
Dave

 

[phishcrazee]

Well, I had the tank crash over Thanksgiving, so could that be why the numbers are so stinkin' low? I did nothing BUT change water after that, and have changed out basically all the water of the 75 gallon = 29 gallon sump. I use Reef Crystals and the test is from Seachem- there are 3 tests in the kit 2 for different types of alkalinity and one for magnesium. I will test it again to make sure, but it seems pretty foolproof

 

[matt the fiddler]

With numbers that low, I would be thinking bad testkit..... Based on my research, it is REALLY hard to have mag get that low... I woudl post on the chemestry forum with Randy - if you double check test kits, BEFORE you take any action.


Reef Crystals has elevated Magnesium.. hmm that is strange...



How is your cortaline alge growth?

 

[waverz]

No way it can be that low, get a different kit.

Matt have you checked your RC's for mag? Mine only tests at 1100 using salifert kits.

 

[phishcrazee]

So we tested it again and it came out the same, BUT we realized we were reading the tests results backwards The test kit is sort of confusing....... my husband read it wrong too, and he has a PhD from Harvard folks and is a chemistry professor, so it wasn't just me, lol.

 

[tmz]

<a href=showthread.php?s=&postid=11400105#post11400105 target=_blank>Originally posted</a> by phishcrazee
So we tested it again and it came out the same, BUT we realized we were reading the tests results backwards The test kit is sort of confusing....... my husband read it wrong too, and he has a PhD from Harvard folks and is a chemistry professor, so it wasn't just me, lol.

:rollface: This hobby is certainly humbling.

 

[matt the fiddler]

I am switching to RC from IO.. so I am going off of memory now..
I thought it was 1350 or so...

I use salfiert kits to test my mag,, and have a gallon of Randy's that I add as needed now...

 

[matt the fiddler]

http://www.drsfostersmith.com/product/add_info.cfm?pCatId=4856


Parameter Suggested Level:
Reef Aquarium Suggested Level:
FOWLR Aquarium Average Level:
Coral Reefs
Specific Gravity 1.023 - 1.025 1.020 - 1.025 1.025
Temperature 72 - 78°F 72 - 78°F 82°F
pH 8.1 - 8.4 8.1 - 8.4 8.0 - 8.5
Alkalinity 8 - 12 dKH 8 - 12 dKH 6 - 8 dKH
Ammonia (NH3) Undetectable Undetectable Near Zero
Nitrite (NO2) Undetectable Undetectable Near Zero
Nitrate - Nitrogen (NO3) < 1.0 ppm < 30 ppm 0.25 ppm
Phosphate (PO4) < 0.2 ppm < 1.0 ppm 0.13 ppm
Calcium 350 - 450 ppm 350 - 450 ppm 380 - 420 ppm
Magnesium 1250 - 1350 ppm 1150 - 1350 ppm 1300 ppm
Iodine 0.06 - 0.10 ppm 0.04 - 0.10 ppm 0.06 ppm
Strontium 8 - 14 ppm 4 - 10 ppm 8 - 10 ppm

 

[phishcrazee]

I have tried to buy a Salfert Alk test for like 2 months now, but each time I went to buy one they were back ordered......... I finally just bought another brand, the Seachem. It might be a little more confusing, but at least I know I'll always be able to get refills etc.

I realize what water parameters are supposed to be Matt, but thanks

 

[waverz]

Matt: have you tried testing your RC's Mg level, last time i did which was like 4 buckets ago, it only tested at 1100 so i have been dosing my water change water.

 

[leeweber85]

<a href=showthread.php?s=&postid=11400105#post11400105 target=_blank>Originally posted</a> by phishcrazee
So we tested it again and it came out the same, BUT we realized we were reading the tests results backwards The test kit is sort of confusing....... my husband read it wrong too, and he has a PhD from Harvard folks and is a chemistry professor, so it wasn't just me, lol.

HAHA!! If I recall, Ned was giving me a hard time at the swap(spring 06) for not understanding Bob's salifert Mag test kit.

Look who's laughing now!

 

[matt the fiddler]

Waverez, where were you running your specific gravity when you test? i am assuming you are .026 ... (and of course knowing you that it is stable ) right?


I have a box of RC, but it is unopened. I am finishing off my IO first..... probably a few more months till it is opened up...

I have my MAG on standby in the meantime.


that IS good to know though....

 

[phishcrazee]

<a href=showthread.php?s=&postid=11408589#post11408589 target=_blank>Originally posted</a> by leeweber85
HAHA!! If I recall, Ned was giving me a hard time at the swap(spring 06) for not understanding Bob's salifert Mag test kit.

Look who's laughing now!

Well, let's just say that ANY magnesium test is not exactly a piece of cake