Ugh, These Blasted Test Kits!...And Maybe A Little Kalkwasser Seesaw Effect? – 03/18/08
Yep, admittedly I fell prey to bad test kits, first with alkalinity and then with magnesium.
<<Very common, in my opinion>>
Here is my issue, 1000 gallon system, my reactor used to be able to maintain Alk and calc at appropriate levels, the test kit I was using (Red Sea as I couldn’t get Salifert at the time)
<<Do try Seachem’s line of test kits…good quality for value>>
for magnesium was reading 1200 ppm. Little did I know it was below that by 200ppm per my Elos kit,
<<I’m not familiar with this brand/manufacturer…though I do seem to recall favorable comments from Bob re>>
and I was using Kalk which was eroding it further.
<<Mmm, yes…I’m not absolutely certain of the science behind it, but I believe it is something to do with the addition of Kalkwasser increasing the precipitation nuclei of the water column, thus promoting the disproportionate loss of Magnesium>>
Needless to say I fell into this desperate addition of varying buffers to maintain Alk and calcium until magnesium finally hit 1300+ (I'd like to stabilize it at 1400, I’m running Zeo Mag in my reactor and it’s putting out 1350).
<<I think it likely the reactors and the Kalkwasser additions are battling each other…probably best to discontinue the latter>>
So, long story short, tested my levels last night, Mag 1300, Alk 8, CA 400. My reactor ran all day, is well tuned in with a pH of 6.5 and Alk output off the scale. I dosed Kalk for a while today to raise pH as it was floating around 8.1 and I wanted to get it higher (dripping maybe 20 drips per minute, in a 1000 gal system I thought it was just about right). Tested Alk tonight and it was 7, CA 360 and Mag 1200!
<<Refer to my previous statement re the Kalkwasser use>>
I do have a little detritus but not a big buildup. I don’t understand why I can’t nail down solid levels. I increased the CA reactor output and it’s a steady stream, but I am really wondering at this point if I am not best off adding another CA reactor.
<<This would be preferable to the Kalkwasser additions>>
I do have heavy SPS but I can’t believe they are sucking that much calcium.
<<If exhibiting heavy or even just “good” growth their demand can be considerable>>
I am beginning to wonder if I am not in some type of runaway supplement nightmare
<<…yes>>
(I add all according to directions), but the sheer fact that Mag fell by 100 in a day (per my Elos test), indicates to me stop dripping Kalk, use Seachem’s buffer for pH if need be, and dose mg according to directions until it stabilizes.
<<Sounds like a plan>>
I don’t have any nutrient sinks that I know of (only DSB is a DSB 30 gal trash but it has no detritus in it).
Any help is greatly appreciated!
<<Stopping the Kalkwasser dosing and stepping-up the Calcium reactor(s) should make a dif…oh!..as well as a large water change to help bring all back in “balance.” Regards, EricR>>

Water Chemistry Help!  Mg... KH interaction, fixing  3/15/08
Good Day Crew!!
<Hello again.>
As suggested we bought a magnesium test kit and tested our magnesium...it was around 1000 yesterday and I’m not sure if I am just having a hard time understanding or reading the directions on the tech-m bottle from Kent, but it says " test magnesium in aquarium, then add tech-m at the rate of 1ml per gallon aquarium capacity per day to bring the level to between 1250-1350ppm, this will raise the level by 18.3 ppm per day”. Fine...so does that really mean that for my 180gal I have to add 180ml? Seems like A LOT....?!
<Yes, one ml per gallon is correct as per Kent’s directions, it does take quite a bit of this product to get the magnesium up to an acceptable level, less of it to keep it there.>
Not sure, anyways I only had 70ml left so I put it in slowly yesterday (around 1:30pm) our levels were: dKH 14,phosphates 0, nitrates 30 (water changes needed more frequently to lower right?),
<Yes, to aid the reduction of KH also.>
calcium 360, magnesium 1000, ph 8.2, total Alk 5.5 mEq/l.
<Test your mixed up water for these levels also to be sure the levels are more balanced (lower KH, higher Ca and Mg).>
After I tested I added the equiv of 100gal of the tropic marine calcium powder, topped up my sump ( right now its just tap water but we have an R.O unit...is going to be installed when we move in 1.5 months) added the 70ml of magnesium and that’s it.
<Test your tap water for nitrate also, if it is the source then water changes will do you no good in that regard.>
This morning around 10:30am I tested again... magnesium 1000, total Alk 5meq/l, calcium 340ppm, dKH 16, nitrates 30ppm, ph 8.2 and then changed to 8.1 by the end of testing.
This morning I fed the tank some Cyclops, rotifers, brine shrimp (all 3 of those mentioned were frozen) and a small amount of phyto (bottled).
Any suggestions to make things equal out?
<You need some water changes to bring down the KH. With a good quality salt this should also raise you Ca a bit, as well as Mg. Do test your makeup water, I do suspect the tap water could be making your KH numbers so high.>
I’m having a hard time interpreting the results, kind of late but we're just really starting to get into the testing and real understanding of water chemistry..... and yes, the purple up is gone!!!
<Great! Keep reading and testing, you will get the hang of things with vigilance and time/experience. You are not too far off here. The magnesium definitely needs to come up, 1250 or a bit more. Also, bring your KH down, as well as the nitrate. Good luck, Scott V.>

Magnesium Gluconate 10/27/07
Dear WetWebMedia-Team,
I have a question on raising the magnesium level. I have read on your site that you can raise calcium levels by adding calcium gluconate instead of CaCl to prevent chloride from accumulating. Can one analogously use magnesium gluconate to raise the magnesium level if necessary?
<I don't see why not. Mg gluconate is just another salt of gluconate.>
I am asking because I already have pure magnesium gluconate at home for supplementing pet food and when calculating molar mass I come to the result that it contains approximately 5.7 % per weight magnesium.
I am just not sure if magnesium in the form of gluconate could have any adverse effects (if administered to the tank slowly and properly, of course) or if it will stay in the water column at all.
<The gluconate is a sugar and so you'll have to be mindful of that. But so long as you're not adding heaps of it at a time, it shouldn't be a problem.>
Thank you & best regards,
Alex
<Best,
Sara M.>

Chloride Ion Buildup From Dosing Magnesium Chloride? – 10/04/07
Crew,
<<Brett>>
I understand that the long term use of calcium chloride as the main means of calcium supplementation is frowned upon due to the potential buildup of excess chloride ions.
<<True, though I think this is rare and often limited to extreme cases where the product is likely “abused” and regular aquarium maintenance/husbandry is neglected>>
I recently started dosing Magnesium Chloride to correct a low Magnesium problem.
<<This is generally a seldom /not often needed adjustment unless heavy Kalkwasser use is depleting the Magnesium from the system>>
Does long term use of Magnesium Chloride suffer from the same drawback?
<<Maybe...if also overused/abused and frequent water changes are lacking. Magnesium Sulphate might be a better “heavy use” long-term solution but the Chloride form is easier for the organisms to use/metabolize than the Sulphate form, as I understand it...kind of a “Catch-22.”>>
What about strontium chloride?
<<I think an over accumulation/imbalance of any chloride ion should be avoided...but most chemical-balance issues can be rectified with the correct water-change regimen>>
What is the best way to raise/maintain Magnesium?
<<Infrequent adjustments can be made using simple Epsom Salts (Magnesium Sulphate), but, mainly because the effects of impurities re is unknown, anything more than infrequent use should probably be with a proprietary aquarium product like Seachem’s ‘Reef Advantage Magnesium’ (which consequently, is a “blend” of Magnesium Chloride and Magnesium Sulphate)>>
I dose Kalkwasser with the slurry method and use SeaChem's Calcium and Alkalinity supplements per GARF's bullet-proof reef suggested method.
<<I am a BIG fan of most all Seachem’s product line>>
I recently noticed that the SeaChem Calcium supplement that I use to raise Calcium is Calcium Chloride based.
<<Yes, this is the most often/easily used “booster” re>>
It also contains Magnesium and Strontium Chloride. I am switching to a Calcium reactor and Kalkwasser reactor/top off unit. Is it a good idea to mix Magnesium chips in with the Calcium reactor media to maintain Magnesium?
<<My experience re was less than stellar. It didn’t cause any problems that I am aware, but I didn’t really notice much difference/improvement, which may well be put to the source/quality of the material used (I think there are several options available now). It is worth trying/drawing your own conclusions I think>>
As always, thank you for your time!
Brett
<<Happy to share. EricR>>

 

Re: Chloride Ion Buildup From Dosing Magnesium Chloride? – 10/05/07
EricR,
<<Brett>>
Thank you for your feedback!
<<Quite welcome>>
I was dosing too much Kalkwasser slurry when my Magnesium level dropped - as you expected and I have since read :-).
<<I see>>
This coincided with a hiatus to my normal testing diligence so I ended up with Calcium levels in the high 500's, dKH around 7 and Magnesium around 1050. My SPS and Maxima clams were not happy and started fading, so I started testing again.
<<Close, daily observation of the organisms in our tanks is a good way to measure/monitor the health and status of/changes to the system>>
Over a few weeks I got my levels back in order - 400, 9-10, 1100 (still trying to raise the Magnesium). I am continuing to test and tweak my dosing regimen and trying to do 15% weekly water changes.
<<Maybe a larger percentage but less frequent regime would be of more benefit right now>>
SPS colors have since returned to full bloom.
<<Excellent>>
I used Seachem’s Reef Advantage Magnesium to raise my Magnesium levels at first before switching to ESV's liquid Magnesium supplement.
<<Also a good product>>
The liquid supplement was much easier to add since I did not have to try and get it to dissolve first but it is 100% Magnesium Chloride. It sounds like I should be able to get to a point where I only use Magnesium Chloride as a periodic boost so that should be ok.
<<Agreed>>
I will experiment with Magnesium in the calcium reactor. I am sure that will take months to vet due to the slow nature of the make a change, test for one or two weeks and adjust loop.
<<Keep in mind the reactor is for “maintaining” not for “boosting”…>>
Do you think that adding Reef Advantage Magnesium to a calcium reactor is a bad idea?
<<Mmm, yes… Too much trouble and will dissolve much too fast…best to dose as prescribed by the manufacturer>>
Or should I look for a media designed for reactors?
<<This would be best>>
Thanks again.
Brett

Magnesium effect on algae and bamboo shark  - 05/26/07
Hello WWM crew,
   <Dave>
  Great site, the aquarist bible. I have 2 questions that I've been researching, that I was hoping you could help with. I have been having a problem with algae in my 100 gallon tank. Not sure if its hair algae or Bryopsis. I use RO/DI water doing water changes, 5 gallons a week. I also added a PhosBan reactor
<For? You have measurable amounts of soluble phosphate? How much, from what source/s?>
with Rio
<I would "watch" this pump... and would NOT run with a shark present... due to ferrous/Ampullae of Lorenzini issue>
400 pushing it, about a month ago. Lighting consists of 2 150 watt halides and 4 55 watt pc's. Halides stay on for 10 hrs, pc's for 12hrs. Long story short, algae is taking over. I try not overfeed flakes or Mysis once a day, alternating between the Mysis and flake daily, for 8 fish. I was reading here:( http://www.reefcentral.com/forums/showthread.php?s=&threadid=1113109&perpage=25&pagenumber=1 )
  that a good prevention for algae is to boost your magnesium.
<Mmm, no... not unless the proportion is off...>
Any thoughts on this? Also I have a month old bamboo cat shark that is temporarily in this tank until i move him into a 300 gallon pond designed especially for him. Will the magnesium boost effect him? Thank you for all your help. Thanks Dave
   <... keep reading. Bob Fenner>

OOOooops.  HIGH Magnesium!! - 4/28/07
I wonder how many Chemistry related questions start out with the title of "Ooooops." I'd imagine not as many as should...lol.
<Indeed…>
Well, I did something stupid and am hoping for some advice. About every 2 days, I mix up 2 or 3 gallons of Kalkwasser. Let's see, today's Friday so it must have been Tuesday. Yes, on Tuesday, I grabbed one of my gallon jugs, poured it into my drip jug and set it up dripping into my sump over night. This morning, I had
to move a couple empty mixing jugs for some reason. Low and Behold, there's the empty gallon jug that I used Tuesday night....labeled....Mg Supplement!!!!  
<Uh-oh.>
Yep, I dosed almost an entire gallon of Mg Supplement (Randy
Holmes recipe using just Epsom Salt) instead of my jug of Kalkwasser.  Well, I rushed to my tank and everything appears to be just fine. In fact, everything actually looks really good....lol.
<Good sign.>
Anyway, I realized this right before having to leave for work so couldn't do anything about it. I'm home now and just tested my Mg. I'm not sure how to read the results. I am using a Salifert test kit. Using the 1 ml syringe, I drew the Mg-3 reagent in as
instructed. I then emptied the entire contents and still needed to add more. I drew the reagent into the syringe again, filled the syringe the same amount I did the first time. From this I added until I got my color change. Holding the syringe tip up, I'm reading the plunger at .78. So, the first full syringe puts me at 1500 ppm. .78 would put me at 330 ppm. Does that mean that I'm at 1830 ppm?
<Yes, that is correct.  The relationship is linear and additive.  Just add the results from each syringe together.>
Normally, I try to keep my Mg at about 1330-1350.
Obviously, I'm just a tad bit high!!!
<It’s not so bad.  A reasonable range is 1300-1500, so you are not ridiculously above this.  One would wonder how high the sulfate levels are also, although this should also not be in a problematic range.>
Any suggestions on what I should do?
<If nothing is reacting badly, I would not panic.  Change water as usual and keep checking Ca levels.>
Any advice would be great!!!  What are the effects of HIGH Mg levels?
<There are not a lot of known effects of high magnesium, it can vary quite a bit.  The most likely victim would be the snails, as the magnesium acts as a muscle relaxant.  If your snails seem particularly lazy, you might want to accelerate water changes.
Links you may have already read, but in case you haven’t:
http://www.wetwebmedia.com/mgmarfaqs.htm
http://www.wetwebmedia.com/alkalinity.htm
http://www.advancedaquarist.com/issues/oct2003/chem.htm
It should be fine.  Alex>

Mg & MACNA  4/17/04
Hello,
        I've recently discovered that  the Tropic Marin salt mix I'm using only has 960-990 ppm of Mg. So I want to  raise it to 1050 ppm in my make-up water, before adding to the tank in the  form of a water change. I already have Epsom salts, but recently read an article  about how sulfate levels can get too high, via the Mg  sulfate. In this  case is it alright to use the Epsom salts long term/permanently?
<Is almost always no problem>
Or  should I use Mg chloride?
<Could use... though there is some downside to excess chloride as well... Again, either/both are not really problematical>
   What's the acceptable range of sulfate in a marine tank with live rock, red headed neon Goby and xenia?
<A healthy aquarium (or. seawater) typically has sulfate levels of about 2700...>
Is there such a thing as a sulfate test kit made for this hobby?
<Mmm... not made for aquariums per se as far as I'm aware... but there are such assays... see Hach's, LaMotte's et al. sites...>
I  also know that long term calcium chloride use can cause problems. Does the  same potential problem exist with  Mg chloride use?
<Mmm, yes... but once again, with serial dilution (regular water change outs...) not simple addition, top-off... not a problem>
        Also, how do I get my hands on  the MACNA XVII, Expanded Horizons video? Is it for sale? Is it for  free? Is it available at my local library?
<Maybe... Please contact the "parent" organization (MASNA) re: http://www.masna.org/>
     Thanks for all that you've done to help make  this fun hobby a success,  
Greg
<Welcome. Bob Fenner>

What's the Diff. between Magnesium and Molybdenum?   2/26/07
<Greetings, Mich here.>
Molybdenum and magnesium... are they diff. substances?
<Yes.  Chemically notated MoO42- and Mg2+ respectively.> <<Mmm, just the elemental Mo and Mg symbols for these? RMF>>
I think it is a yes...or is Molybdenum just another form of magnesium?
<No.>
Because Red Sea produces...Molybdenum...they don't produce magnesium...and Seachem sells magnesium but not Molybdenum.... isn't it weird?
<Mmm, no stranger than anything else.>
What's the effect of Molybdenum to reef tank?
<Possibly a micronutrient.>
Which is more important ??
<Magnesium.>
I am using magnesium only...should I put in Molybdenum too?
<No.>
What's the effect to my corals if I used Molybdenum too? :)
<As far as I'm aware the science isn't well understood.  RMF any comment?  -Mich> <<Not necessary in any system I've ever read about, encountered to add this micro-nutrient... is only necessary in very small amounts... supplied by salt mix, foods... RMF>

Reef tank problems Calcium, Alkalinity, Magnesium – 2/20/07
Hello,
<Hi Bryan, Brenda here>
I have a 90 gallon saltwater tank that has been set up for almost eight years. For the first seven years I used 4x96W PC with actinic/white bulbs and never had any major problems. My tank had a lot of mushrooms, polyps, xenia, leathers and a few hard corals like cup corals/pagodas. Then I switched to 250W MH lighting with 14K bulbs. Over the course of 18 months I lost almost all of my coral. I found out that my calcium and alkalinity were really low (due to the MH lighting I guess).
<No, Not the lighting.>
I had been dosing just Kalkwasser up to this point, which apparently wasn't enough to meet the needs of my reef.
<Are you testing for Magnesium?>
I have since started using B-ionic two-part solution. This has helped my calcium and alkalinity to some degree but I cannot seem to keep the Ca over 380. My Alk is usually around 3.8 to 4.2. I had acquired some new corals awhile back (polyps and Montipora) and they are starting to look washed out and the polyps aren't opening up much now. My tank has very little coralline and what is there looks really washed out. I'm not sure what the problem is, but I'm about to give up on MH and go back to PC since I never had trouble before. My MH lights are 8 inches above water surface and I run them 10-11 hours a day. Do you think my tank is getting too much light or not enough?
<Not a lighting issue>
The bulbs are only a few months old (ordered from Hamilton). Why can't I keep my calcium above 380? I've even been doing double doses of B-ionic and it doesn't seem to make much difference on the Ca levels. I started adding Fiji Gold on top of Kalkwasser and Bi-ionic. My sand bed is only about one inch deep and is kind of old. Is there a possible buffering problem? I do 7-10 gallon water changes every 5-10 days using r/o water.
<Sounds like you are low on Magnesium.  Purchase a Magnesium test kit.  Magnesium should be in the 1300 – 1500 range.  Here is an article to help you understand the importance of Magnesium, and its relationship to Calcium and Alkalinity.  http://www.advancedaquarist.com/issues/oct2003/chem.htm  >
Any thoughts would be appreciated.
-Bryan
<Any time Bryan!  Good luck!  Brenda>

Magnesium and Sulfate Question – 2/8/07
Hello!
<Hi Chris, Brenda here>
I've been struggling to get my Calcium levels to rise and stay at a good level.  I seem to be averaging about 290 ppm.  My Magnesium level is about 1140 ppm at the time, and I was told to raise this level so that it might allow for a higher Calcium level to be maintained.
<Yes, Magnesium should be in the 1300 – 1500 ppm range.>
I've been using calcium chloride (1/2 tsp mixed into top off water) to supplement for Calcium while maintaining good alkalinity levels.
<I hope you are not mixing your calcium and alkalinity supplements together in your top off water.>
I use this almost daily with the results averaging the levels mentioned above, and I wouldn't know just how the chloride is reacting in my tank.  I'm running a 75 gallon reef tank, and my question for now is can I use Epsom Salt as a means for a Magnesium supplement, and how does Sulfate react in the tank, can it become toxic?  You're website has been a world of help, answering most of the questions I ever have.
<Thank you for the positive feedback!  Yes, you can use Epsom Salt.  Here is an excellent article written by Randy Holmes-Farley.   It has a lot of useful information.  Also read the links provided within the article, and check out the calculator for proper dosing.   http://reefkeeping.com/issues/2006-07/rhf/index.php >
Thank you so much for the time you all have given to help others.  
Sincerely,
Chris Brant
<Your welcome, I hope this helps!   Brenda>

Re: Ich, Low pH, Low Calcium, Possibly Elevated Magnesium    1/17/06
<Hi Jennifer, Mich here again.>
Thanks.. I'll try the baking soda.. I got a reef testing kit the other day. all is great except the calcium is low..300.
<This may be contributing to your snail/limpet problem.  I suspect your magnesium level is also elevated, if your calcium level is low.  The magnesium may be acting as a muscle relaxant, which may explain why the snails are alive, but the not moving.  Adding calcium will lower the magnesium levels and may remedy the situation.  Try to increase your calcium levels up to around 400 mg/L.
  Now I have another problem (it's always something, huh?), ok, here goes.. I've got a 10 gal QT set up with a clown, a firefish and a damsel.  I got ich in my DT so I put all fish in the QT and I'm going to run the DT fallow for at least 6 weeks.  
<Very good.>
They've been in the QT for a week and the damsel is not doing well.
<Sorry.>
Here's what I've done. I treated with CopperSafe and have been testing water daily.
<And the levels are in the recommended therapeutic range?>
I've been doing daily water changes (up to 50%) to keep ammonia, nitrite and nitrates down. Nitrites at .25, all else at 0.  
<This is important.>
Don't have any kind of bio media in there since whatever I have in the DT might have ich and I don't want to put that in the QT.
<No matter, the copper will kill off most of the biological filtration anyway.>
The damsel's color is not good, not eating, gills pumping and she's not really swimming.  Could the CopperSafe (chelated copper) being doing this to her?
<More likely the ich.>
Any thoughts on how to save her?  
<Not really much you can do but keep the copper levels in the recommended therapeutic range, keep the ammonia / nitrite/ nitrate levels in check via water changes and give her time.>  
Thanks!
<Welcome!  -Mich>

Re: Ich, Low pH, Low Calcium, Possibly Elevated Magnesium   1/19/07
<Hello again Jennifer, Mich here.>
Could the mg/calcium be the reason I just lost a porcelain crab?
<Hard to say, there are many possibilities.>
The other one's not looking all that great either.  The coral banded and green crab are bit lethargic as well. The only thing moving are the algae conchs.
<Can you test your magnesium levels?>
I've been adding Kent's liquid calcium everyday  but I'm afraid of adding too much. Any advice as to how much to add? (I don't have a Kalkwasser) Test results today were 340.
<I would aggressively follow the directions.>
As for my QT my damsel seems to be hanging in there.  I'm just going to have to reside myself to daily water changes.  
  I do have a few more questions if you would be so kind...since I am new to this crazy hobby (yes, one has to be crazy to get into it or you will be shortly thereafter)
<Hehe!  We are in agreement here!>
I didn't set up things they way I should have (budget issues).  
<Usually makes more economic sense to go slowly.>
I currently have 60# of crushed Florida coral in my 55 gal and want to switch it out for sand (after I work out above issues).
<You can do this but you don't need to.  Can keep it as is, or add sand.>
Should I do this all at once, in sections; if so should I remove the inverts due to the nitrite spikes?
Also, I want to add live rock.
<Oh!  You don't have any live rock?  This would be the first thing I would do.  This will greatly increase your filtration and overall stability.>
How much for a 55 gal?
<At least 55 pounds, 100 pounds or more would be better.>
Does it depend on the livestock? Thank you for all your help and expertise!!!!  
<Welcome!  -Mich>
Jennifer

Re: Ich, Low pH, Low Calcium, Possibly Elevated Magnesium, system improvements...   1/19/07
Ok, so first order of business.. I'll get some live rock...I just bought a CoralLife protein skimmer.. hopefully that will help with some issues.  
<Skimmer and live rock will both greatly benefit your tank.>
I tried to find a magnesium test today at some of the LFS and no one had any. They all said "They aren't very reliable".  
<Hmm, interesting.>
  Thank you for all of your invaluable advice and help!!  
<Welcome!  Good luck with your setup!  -Mich>
Jennifer  P.S. I'm sure you'll be hearing from me again!!

Epsom Salt in Main display -- safe?  - 3/1/2006
Hi Dear Crew members,
   <Cam>
  I really appreciate your existence and help given to all of us in this fantastic hobby.
   <Welcome>
  I have a Redbar Anthias, measured 3 inch and  2 days ago, it got a pop eye on its left eye. The pop eye got bigger by the day & I am bent on dosing Epsom Salt as suggested by your web sites after goin through the FAQs. Before I do it, I need some clarification. so, please help.
   <Will try, am trying>
  Beside the pop eyed Anthias, the main display houses Emperor angel (6 inch), Regal angel ( 3 inch), Red Shoulder fairy wrasse, Cleaner wrasse ( this baby has been with us for more than 1.5 year, it eats pellets & flakes), Coral beauty Dwarf angel, Firefish goby and one SUN Coral. I suppose Epsom would not affect them negatively?
   <Not in small concentration, no>
  Question is: Is it safe to dose Epsom Salt in Main display? Some FAQs advised to take patient out into QT rather than treating in Main display, but some said OK with main display. Please help me by one more reassurance that it is OK to dose Epsom Salt in "Main display tank"?
   <Is okay>
  The dosage is one table spoon per 5 gallon and repeat every 3 days, if eye is still popped... is this confirmed?
   <... I would cut this dosage by half... a level teaspoon per ten gallons of actual water volume, AND no need to re-treat unless you change water out...>
  Sorry for asking as I have not done it before. so got a bit cold feet. Hope you understand!   
  Cheers!
  Best regards.
<Do. Bob Fenner>

Please Help! -- Mg damage to corals? Sclera. health - 2/28/2006
Hi Crew,
<Greg>
I hope I am worrying needlessly, but I am concerned I might have an unknown coral predator or a water parameter problem with my 180g reef.  My main concern is one Acropora with approximately a pea-sized exposed skeleton near the base of one branch and ½” of skeleton exposed on one tip.  A brown mucous-thread-like substance covered the Acropora, with dead tissue trapped in the bottom of this mucous net.  I siphoned-off the mucous and dead tissue, cut off the dead tip of one branch, then dispensed a tank water + Lugol’s solution over the remaining bare skeletal areas.  I just fear that this area of necrosis might be spreading.  This Acropora is placed approximately 8 inches from a 7” Crocea clam (which occasionally produces a similar-looking mucous-like “net” near the byssal opening).  So I am unsure if the Acropora coating was from the Crocea or if it was produced by the coral.
<Mmmm>
Two days prior to this happening I did move a rock that was attached to this Acropora and one tip was broken off the Acropora.  This has never been an issue in the past as new flesh would cover the exposed skeleton within a week and new branches would form.  Possibly this initial stress is what led to the current tissue necrosis. Current water parameters: Temp=77°F, Salinity=1.024, pH=8.1, alk=3.2 meq/L, Ammonia=0, Nitrite=0, Nitrate~1ppm, Ca=440ppm, PO4={below meas. Limits}, Silicate=0).  I did also increase temperature on my heaters from 76°F to 77°F a few days ago.  I performed a 32g water change at the same time.
A little history…
About two weeks ago, I noticed that all of my Montiporas were becoming much lighter in color.  I was not overly concerned because they have lightened and darkened in color several times over their 2 years in my tank and they continue to grow well.  Although water parameters have always remained within acceptable ranges previously,
my salinity dropped from 1.025 to 1.022
<This is a huge difference>
over the course of a day just before the Montiporas changed color a few weeks ago.  A snail had stuck my makeup water float switch in the “on” position for a day, flooding my 100g refugium and diluting the water with RO/Kalk mixture.
<No fun>
My pH measured 8.2 so I was only concerned about the sudden change in salinity (makeup water flows at only 10gpd).  I removed 10 gallons of tank water and slowly added 10 gallons of very high salinity water until tank salinity measured 1.023.  The following day, I repeated this procedure until the salinity reached 1.024.  All fish, corals, clams, other inverts appeared to be unstressed so I assumed that worst case, this might have induced a temporary color change in the Montiporas.
<Takes a while to show... weeks, months>
Since my alkalinity and pH have always remained near the low end of acceptable (pH=8.0-8.1, alk=2.5-3 meq/L) despite using a Kalkwasser reactor for top-off and the addition of Na2CO3 and NaCO3, I bought a Mg test kit to determine if a low Mg level was partially responsible for low alkalinity (Ca=440 ppm).  Mg measured 1,140 ppm
<Close enough...>
so I mixed 10 teaspoons of Seachem Reef Mg in 1 pint of RO water and dripped this into the pump intake in my refugium.  An hour later I repeated this.  According to Seachem’s label, I would have needed to repeat this process a few more times to reach the desired 1,300 ppm but I noticed another Acropora (near the return line) with mucous-like threads waving from its polyps.  I was concerned that I might have changed the Mg level too quickly so I made no further changes to the tank for the next two days.
<Good>
I did continue to noticed these “mucous threads” waving from the Acropora polyps at times.  This is a different Acropora than the one that is currently displaying tissue necrosis.  Could dosing Mg in this way cause tissue necrosis in Acropora?
<Possibly a factor, not likely "the">
This particular coral is not in direct flow of the pump return line.
One Montipora has completely bleached (although polyps are visibly extended) but I did move this coral to a lower light area of the tank when it initially began to bleach.  All other corals (4 Acropora, 1 birdsnest, 1 open brain, 1 pineapple coral, hammer coral, zoos, star polyps, mushrooms, Alveopora) appear to be doing well.  Even the Acropora that had previously produced the mucous-like threads now appears normal.  All inverts appear unstressed as well.
What should I do about the Acropora with the tissue necrosis – is there a way to reverse this spread?  
<You likely have>
If the necrotic area continues to grow, I assume I should frag the coral to save the remainder – correct?
<An approach. I would move this colony to another system, or even shallow, brightly lit sump first myself>
Do you think this in contagious (e.g. should I be doing anything to protect the other corals in my tank)?  Unfortunately I do not have a picture to send yet, but I can follow-up when I return home tonight if needed.
Thank you in advance for your help!!!
--Greg
<I doubt you have a pathogen at play here. Very likely the bit of trouble you've observed is/was due to the change n spg... I would not over-react here. Bob Fenner>

Re: Please Help! -- Mg damage to corals?  - 3/1/2006
Bob,
<Greg>
Thank you so much for your input (or at least putting my mind at ease) -- and for taking the time to read my email.  I will continue to watch this
Acropora, but no additional skeletal areas appear to be exposed tonight.
<Good>
I refer all of my fellow reefers to the WWM search for answers to their questions.  You and the WWM crew offer an invaluable service to aquarists!
--Greg
<We're very glad to share. Bob Fenner>

Epsom Salt/Magnesium    2/17/06
Dear Mr. Fenner & Staff, <James today.>
I recently had a professional lab run some test on my water.
Alk- 3.0
CA- 348
PH- 8.2
MG- 880
Sal- 1.026 (my reading)
Phosphates- 0
My question is my Magnesium seems to be very low in my 90 gallon reef tank. I have had a problem with slow growth and was wondering if the low numbers on the Magnesium could be the culprit. <Not the only.> I called up the tech support at Seachem and she suggested that maybe my salt was low in magnesium. I use Tropic Marin pro reef and don't believe that to be the case. Water changes are performed every two weeks religiously. I went out and bought a Magnesium test kit and Seachem Magnesium. After the reading the label I would need a few bottles to get me back in the 1,000 mg range. Would it be possible to use common Epson salt. <Yes, might consider the Pharm grade.>
Thanks once again for all your help! <You're welcome.  James (Salty Dog)>

High Magnesium Level 01/19/06
Hi Guys <<Hello Tom - Ted here>>. Bob Fenner said my problem with declining coralline algae maybe due to a Mg imbalance. The Mg level is off the chart measuring 1500 +. The Ca is at 430. I couldn't find any article to say how to lower the Mg. <<Lower the magnesium level by doing water changes and quit supplementing magnesium. Please read this article on alkalinity by Anthony Calfo (http://www.wetwebmedia.com/alkalinity.htm).>> Is 1500 + too high?<<Yes>> If not I'll work on the possible predation problem that he suggested.
Thanks for all the help.
Tom  
<<You're welcome and good luck - Ted>>

Magnesium In A FOWLR - 07/13/05
Hello,
<<Hi>>
I was just reading the article on alkalinity and a Kalkwasser stirrer. It mentions the magnesium level should be 3x that of the calcium level.
<<Yes...about.>>
I use natural seawater.  So I need to find a magnesium test kit and start adding magnesium right?
<<Not necessarily.>>
I test for nitrates, kH, ca, ph, nitrites, ammonia, phosphates, salinity.
<<ok>>
Is there anything else I should be worrying about in my FOWLR tank as magnesium is a new one to me?
<<I doubt you need to worry about the magnesium, really.  As this is a FOWLR tank, you don't have a large quantity of calcifying organisms (e.g. - SPS/LPS corals).  If you are applying frequent partial water changes you're likely supplying all the magnesium this tank needs.>>
I supplement trace elements as well.
<<Another waste of money in my opinion.  Again, the water changes will supply.>>
Many Thanks,
James.
<<Regards, Eric R.>>

Re: FIN ROT & USING MAGNESIUM
Dear MacL the site you put me on to is about nitrates, is this what you
where talking about or a mistake. <Hey Chris, if you look down into the discussion you'll see where calcium, magnesium and alkalinity fit into the balance as far as nitrates go.  More importantly is the discussion about how they all fall into balance.  I just got through rereading Martin Moe's book. Man does he have a lot of wonderful things to say but the important part is that saltwater is a balancing act.  Let me attach what Rusty said to this email so you don't have to go searching for it. Let me know if it helps you. MacL
Ta Chris

Re: FIN ROT & USING MAGNESIUM
Hello WWMCrew, <Hi Chris, sorry for the delay I've been at MACNA, so wasn't around to answer.>
MacL your info has given me a more insight into what's going on, so if I do more water changes to get my levels closer then bump the levels up with powders at the end. <Right!!! The idea is to get your tank into balance and then adjust what you feel necessary but always achieving balance.> What water would you use I can get RO salt water or fresh salt water both are from LFS shops. <It depends on what you are trying to achieve.  RO salt is salt that has everything taken out of it then the chemicals and traces put back in with the salt. Natural ocean water is just that.>  I still cant get my head around not using additives like reef plus iodide strontium and so on, what do you and Andrew use in your tanks. <I use a lot of additives Chris its just that I test very carefully.  The one thing I never fail to use is Kalkwasser because I find it very helpful to my tank balance.> Yes I will get some all-rounder meds for the fin rot, do you know about Melafix if so will this do the job. <Lots of people like Melafix, I'm always very cautious with meds period Chris.  Good luck and keep me up to date MacL>
Thank you for making this so simple Chris

Low magnesium and rising calcium levels 5/26/04
I hope you can help me determine if this is a problem or not. For the last several months, my magnesium levels have averaged around 1080.
<this is honestly fine if your calcium is 350-400ppm... too many hardcore reef aquarists advise higher numbers (unrealistic) without reckoning the tanks likely lower daily demand for either said element>>
I added 20 mgs every couple of weeks to the 75 gallon reef and called it good. My Ca tended to hang around 400 or so, but has always fluctuated somewhat.
<no worries... but do consider a calcium reactor for an upgrade to improve upon this>
In the last four weeks of testing, my calcium levels have been climbing without adding any of the usual SeaChem calcium additive I used to add weekly.
<Hmmm... dissolution of aragonite sand? Is your pH dipping lower than usual at night at the same time. Perhaps the problem>
In fact, last test it was at 460 which is quite high for this tank.
<agreed>
The dkh hangs around 8.3 and is pretty stable.
<very fine... especially in light of the higher Ca>
My question is are the low mg and high and climbing ca related?
<not likely>
Should I worry about either?
<perhaps not... if you do regular partial water changes (10-20% weekly minimum rather than larger monthly ones) then all well IMO>
I use RO water and do about 10-15 percent water change per month.
<a modest/light water change schedule that will keep you at the mercy of a see-saw chemical additives dynamic. Do consider a calcium reactor and more water changes>
Coinciding with this has been bleaching on 1 of my Acropora. I do not know if this is related or not. Any thoughts?
<tough to say on the Acro... many possibilities>
Thanks, Sarah
<best regards, Anthony>

Water movement and magnesium -3/19/04
http://www.thatpetplace.com/MainPro/itemdy00.aspx?T1=F78+0062+0099
Pauley!
I'm still at it. I looked into some of the companies here on the Cape, (one looked pretty good, but I'm holding off, I'm stubborn!) <A big and could be an expensive decision. Take as much time as your animals can take> in the meantime, I'm trying to solve some of the obvious probs for myself, like, water movement. <Excellent, Pam>
There are so many pumps and other "water movers" out there I'm having a bit of a time deciding. <Understand>
What do you think of this small pump? <Aquarium Systems Jet series are well regarded and respected. I would go with some of their larger pumps though. I remember you having a very large tank> I thought of  buying  4 to 6 of them, and placed in tank in strategic areas pointing at each other to create a constant movement. <Excellent but maybe a bit bigger pump?> I suppose I could hook them up to a device that turns them on and off. <No need. You could though>
I have so many dead areas in the tank, and this can't be helping the cyano. <Exactly. You make me happy with your new found knowledge>
I've had the lights off in the tank for 2 days now. Just letting in the daylight. It will have to do. <OK. Likely won't affect the growth of the cyano though. It can grow with minimal lighting sources. May help though>
I'm bringing the salinity up bit by bit, today it's at 1.023. <Excellent, you>
I'm looking for a good ph tester. I do have a LaMotte test, but it's the "matching color" type. Very hard to read! ,I am not a big fan of those either> Sometimes I think it says 7.5 and sometimes I think it says 8.0. I can't figure it out. The dKH is back to 7.8. <Yay!!!!>
Tell me Paul. I know you told me NO MORE DOSING, <Right> but,..........I was reading about low magnesium levels possibly contributing to low ALK and Ca levels. <Not with the amount of water you are now changing. I don't think it is possible.> I DO have a magnesium supp., should I add some? <Nope. Unless you can test for it to ensure it level and necessity for dosing then NO! >And what depletes magnesium in the first place? <High Alk and PH are a couple of items that can lead to magnesium depletion. Some say high rate of growth ini coralline algae will rapidly deplete magnesium as well. None sound like issues  that relate to you.>
Okay, I've probably picked your brain enough for this mailing. I did send an email to the others at wetweb, but you always respond the fastest (pressure!) <I am slow in good ways> so, here I am again, at your door, asking more! <Not a problem. Here I am trying to give you answers. Will talk shortly. ~Paul>
Thank you

Low Magnesium 12/10/03
I have a question for you. Recently my tank has had massive reduction in magnesium. My tank is 120 (uk) gallons with a big profusion of live rock. I have a converted nitrate reductor on tap as a calcium reactor with aragonite media. I have a mixed reef garden tank with the following corals
Stonies
2 colonies of cup coral
1 hammer coral
1 Porites
2 Caulastrea colonies (1 fairly large)
2 faviids
1 pavona colony
3 other leathers and polyps
Now I know reef gardens can suffer with allelopathy (tempered with frequent water changes), but why is my magnesium so low?  My calcium and hardness are fine.
<Hi Jim, Adam at you service today.  My first thoughts are toward verifying the accuracy of your test kit and then to precipitation, and then lastly consumption.  Please do always provide actual test kit readings when relevant (clearly the case for Ca and alk in your situation).  Assuming that your test kit is accurate...  If your alkalinity and/or pH are elevated, this can lead to a precipitation of MgCO3.  This is most likely to occur with the use of very pure Kalkwasser.>
The only problem I can nail it down to is the massive (and I mean massive) growth of my purple corallines, they have been growing like mad. I mean plating outwards. I have literally had to break some plates apart because of their size. I am told by my very reliable LFS, that this upsurge of coralline growth depletes magnesium rather than calcium and carbonate?
<I have heard this too, but cannot confirm or deny it.>
Any of you got ideas? I am supplementing my tank with magnesium supplement now. Mg levels were down to 1080ppm at one point (my fault for not twigging). The out feed from my reactor is around 1450 ppm, which should sustain a reef tank I would have thought.
<Be cautious when using such supplements since they can lead to imbalances of other ions.  The supplement is likely MgSO4 and elevated SO4 can interfere with alkalinity measurements.  Adding 10% or so Dolomite (please acquire this from a reliable source, I have seen other things sold as dolomite here in the US) to your calcium reactor medium can help maintain Mg levels without accumulation of SO4.
Normal Mg is in the 1250-1350ppm range, so your level is fine, and even at 1080ppm, I would not worry unless you start having problems maintaining alkalinity.  FWIW, CaO and CaOH (kalkwasser) are often fairly highly contaminated with MgO and MgOH which explains why despite the high pH, kalkwasser users rarely have problems with Mg levels.  HTH! Adam>

Magnesium Madness!
You guys/gals are the best.
<Thanks for the "props"! I'm lucky to work with some great people here at WWM, and we're lucky to have some awesome readers who share their experiences with their fellow hobbyists! Life is good!>
I searched around the site and see where Anthony talks about Mg chloride as a cheap way to keep that little nasty Mg at 3 times Ca levels.  My Question, Epson Salt is Mg sulfate.  Where does a cheap basset get the good Mg Chloride?  Heavy Kalk use keeps depleting my Mg.  Ca is 380, dKH is 9 and Mg is 800, So sad.  ESV cost me too much.  Wife would divorce me, but I have no liquid assets.  Spent them all on the Tank.   Thanks for your help.  Epson can give me the Mg, but don't want the fish getting the runs, :). Dosing recommendations per gallon always a plus.  Yeah, I know it depends, but something like a teaspoon raises 1 gallon -20 ppm or something along those lines is very helpful.  Brian
<Ya know what? If it were me- and I like keeping things simple- I'd opt for a dry product, like Seachem's "Reef Advantage Calcium", which is relatively inexpensive- about $10 per kilogram, and is easy to use. Or, you can contact a scientific supply store or local high school to see where they order chemicals in bulk...?Alternatively, if you're a hardcore water change nerd like me, you could simply change water on a very frequent (like twice weekly, 5% of tank volume) basis, and let the salt mix be your "magnesium additive". I guess I tend to over-simplify things at times, but I find that water changes usually do the trick, even with frequent kalkwasser use. Hope this inspires you? Regards, Scott F>

Levels question
Hi Bob,
I'd like to know if I have Ca and Mg low (360 and 1100) in my FOWLR, I have to raise both or It's enough only raising Ca level. I know that their relation is 3 to 1 but Mg additives are very expensive.
<Mmm, no. The most readily available, cheap route here is MgSO4, Magnesium Sulfate, aka Epsom Salt>
What can you recommend?
<What do you mean? Recommend for what?>
I won't have these problems if I'd use Tropic Marin salt?
tank you very much
Lorenzo
<Likely not. Bob Fenner>

Reef water chemistry 3/6/03
I picked up a Mg test kit and measure it is about 960mg/L. quite low right??
<not really... just a little low. It should be about 3 times the amount of Calcium and as such is in balance in your tank. A little higher on other (say 400ppm Ca and 1200 ppm Mg) would be nice... but no hurry. Be safe and raise slowly>
And in the letter you told me to stop adding supplements and do
water changes, I have a 125 gallon, how big is the water change need to be??
<3 water changes of 25-50% each in the next 10 days would be nice>
Right now the parameter is
Alk-3.2
Ca-280ppm
pH 8.2
Mg 960mg/L
NO3 5-10ppm
Sal-1.022
Temp 78F
The corals are doing just fine, and nothing seems to be wrong...
<understood... and your chemistry is in balance... just a little flat. No worries.... the water changes will correct that if large enough>
should
I stop adding Mg still even it tends to be low??
<no low my friend... be careful of the dangerously high levels touted by some hardcore stony coral farmers>
And also, what is a good way to change water?? 20 gallons each for 5 days?? Or a 50 gallon change first follow by small ones? Like 15 gallon weekly?
<several medium to large water changes will dilute all nicely as per above>
Eric
<best regards, Anthony>

Substrate getting hard 3/4/03
dear Crew:
<cheers>
I have seen a situation in my tank where i just cannot keep up my calcium level. and my substrate is getting very hard, forming stones... and i have been asking around and people told me that my tank is lacking in Mg. is that right??
<not necessarily... the substrate packs from adding too much Ca or adding it too fast>
i have been adding many many alk buffer and ph buffer, liquid calcium and Part A and B additives... but still cannot get it right into the parameter...
<when using 2-parts... use no other supplements for fear of skewing their balance. Also, mix the Ca part vigorously before every single use... it stratifies and will get dosed askew otherwise. The extra buffer added was worse than not mixing though>
right now, i have only around 8.12-8.19 pH and 3.2-3.5 meq alk... should i dump a bunch of mg additives in and see what happens??
<are you serious? You really can't be. I really hope you are childless with decision-making skills like that. Seriously... my suggestion is for you to pick up a Mg test kit... test your water... and then.... dose additives if necessary up to the recommended level. I am sure this is better and safer>
also, when i was trying adding arm and hammer baking soda to try to rise my pH, however, whenever i add it, the pH lowered... why???
<because the chemical soup created in the tank has fostered a precipitous reaction. You need to stop adding all supplements temporarily, do several large water changes in the next 7-10 days, and then simply resume dosing only the 2-part supplements exactly as directed on the package and orchestrated (tweaked if necessary) by water test results. This solution requires reading the instructions on several packages. :) The marine-nazi... Anthony
Eric

Magnesium
Hey Guys, Can you give me an idea of the relationship between Mg and Ca in a reef aquarium ?
<magnesium is involved/influential in calcification... a deficiency can impede rates of skeletogenesis markedly. Our goal is to have approximately 3X magnesium as calcium. A value of 400ppm Ca and 1200ppm Mg would be very fine for a tank dominated by scleractinians>
Is there any species that require more Mg than others ?
<we believe that some coralline algae require proportionately more Mg than some corals. If you are not running monospecific displays, please don't worry about spiking or unrealistic ideals/highs... consistency would be more important with safe averages>
Thanks for the help. Wendell A. Nunes
<Happy holidays to the Great White North. Kindly, Anthony>

Ca/ALK and Mg
Hi! Finally I receive my mag test and additive. The readings shows something between 950-1000, so I will start to dose some magnesium daily in order to rise it around 1300-1500??
<no need to go that high, my friend. I suggest that 1200ppm Mg is fine and safe/realistic. 400ppm Calcium and 8-12 dKH ALK will be fine targets>
There is any advise about daytime to dose it, cautions?  Thanks for any input
<simply dose in small amounts and separate from other additives>
Carlos Díaz
<best regards, Anthony>

Low magnesium levels.
Gentlemen, I have measured my magnesium levels and they are between 1050 -1100. Calcium levels are at about 350, DKH around 9.  Would it make sense to increase mag. levels to try to raise the calcium levels closer to 400. Using a calcium reactor and night drip of Kalk.  Thanks in advance.  
<Either would be fine, both would work well together.  There is really no need to push it unless you have a lot of corals with a high demand for calcium. Best Regards, Gage>