Let's talk about Alkalinity, Calcium and Magnesium in an SPS Tank

<a href=showthread.php?s=&postid=10503028#post10503028 target=_blank>Originally posted</a> by teen
is it true that low levels of magnesium can lead to poor colors in sps corals? my alk and calcium are in line, but i dont test for magnesium, and im thinking its on the low side. recently ive been having some browning issues, and i dont know what to blame it on.

I've never seen low mag cause browning issues. My mg was at 900 for a long time before I caught it. None of my corals were brown at the time.

capn_hylinur Sometimes if you are pushing your ca reactor too hard it can cause lower tank pH. The only suggestion is to try and dose some kalk at night. I used to mix a teaspoon of kalk with a little ro/di water and just tossed it in the sump. I did that a few years back when I was having large pH fluctuations. The ultimate solution was to get a different ca reactor that didn't have to work so hard, but that's another story.
 
Yeah getting the right amount of dosing can be challenging and as many people wrote, the more your corals grow the more demands are placed on the tank so you need to adjust things. Sometimes when adjusting you find the parameters bouncing up and down till you get things stable. It can be frustrating trying to get things dialed in but once your do. The tank does well. Getting everything stable is key though. Everyone has brought up that point but it is very true.

Keeping the parameters is nice, keeping it all very stable is great!
 
One thing you don't want to do is wait till your levels are off to add anything Cal. or Alk. or mag. You need to detemin your demand. I have settled in with 1 cup of 2 part calc. and alk. daily and 1 cup of mag 2 part twice a month. If I add some corals then I'll begin monitoring these levels and adjusting upward as needed. You should add calc. and alk. daily to keep it stable.
 
I'd add: a log book is your friend. If you keep a log of what you added and what the reading was on the following day, you can spot trends and correct before you're into bad territory.
You also learn how your particular tank reacts, and you can smooth out the peaks and valleys of calcium/buffer.
 
<a href=showthread.php?s=&postid=10501353#post10501353 target=_blank>Originally posted</a> by jeffbrig

I don't think corals deliberately use (or require) Mg, it's more of an incidental pick-up while building their skeletons. But, maintaining Mg levels is necessary to hold Ca and Alk levels where you want them.
All protein synthesis, DNA replication and most enzymatic process use Mg as a co-factor. It is incredibly important for biosynthesis.

Not trying to be nit-picky just bringing a thought to the table, :) .
 
Joe, I dose with Seachem Reef builder also when my alk gets low. Can you add this when you make your saltwater for a waterchange ? like you do with mag? Or is it better to just mix with ro/di?
 
<a href=showthread.php?s=&postid=10512213#post10512213 target=_blank>Originally posted</a> by bradleyj
Joe, I dose with Seachem Reef builder also when my alk gets low. Can you add this when you make your saltwater for a waterchange ? like you do with mag? Or is it better to just mix with ro/di?

Yeah you can.

This is what I do when I do a waterchange. Fill up the bucket with ro/di water then add the salt. Then add whatever additives I need to get that water the same levels as is in my tank. for the alk and calcium additives I still mix them in a cup of ro/di water before adding it to the new saltwater.
 
But only if you are trying to raise the alk of the new water to bring it to an acceptable level. Trying to add extra, so as to raise your tank alk this way could very likely cause a precipitation effect in the new water. I'm sure this is not not Bradleyj meant, but I wanted to just clarify in case anyone reading this thought this way. :)

BTW Joe, I'm with you on the Magnesium. I found (in this tank and my previous tank) with Mg at 1100ppm or so, I could NEVER get my Ca above 360ppm.
 
<a href=showthread.php?s=&postid=10514102#post10514102 target=_blank>Originally posted</a> by SDguy
But only if you are trying to raise the alk of the new water to bring it to an acceptable level. Trying to add extra, so as to raise your tank alk this way could very likely cause a precipitation effect in the new water.

Good point.

<a href=showthread.php?s=&postid=10514102#post10514102 target=_blank>Originally posted</a> by SDguy
BTW Joe, I'm with you on the Magnesium. I found (in this tank and my previous tank) with Mg at 1100ppm or so, I could NEVER get my Ca above 360ppm.

Yeah so many calcium problems could be fixed faster if people would test their Mg more often. I test mine about as much as I do my calcium.
 
<a href=showthread.php?s=&postid=10508521#post10508521 target=_blank>Originally posted</a> by JB NY

capn_hylinur Sometimes if you are pushing your ca reactor too hard it can cause lower tank pH. The only suggestion is to try and dose some kalk at night. I used to mix a teaspoon of kalk with a little ro/di water and just tossed it in the sump. I did that a few years back when I was having large pH fluctuations. The ultimate solution was to get a different ca reactor that didn't have to work so hard, but that's another story. [/B]

thanks JB NY but I am not running a calcium reactor. For the last year I have been using Randy's article on Solving alk and pH problems. I am due for a water change---maybe I should start over using the b-ionic two part system and try to bring stability back to the pH.?
Is a big flucuation in pH a problem for SPS corals or should it just be ignored and worry about alk calcium and magnesium(those are very stable right now)
 
To my knowledge, corals don't like rapid change in any parameter. I'd try to eliminate any bounce in anything to do with water, though I can't point to any specifics regarding ph. I'd *think* that it might affect the condition/penetrability of their 'skin,' making it more or less vulnerable to bacteria, etc, but that's only guesswork. The more 24/7 any 'good' situation is, the more corals are going to settle down and do their thing: I think that's safe to say.
 
Does anyone have concerns over the rise in sulfate when adding epsom salt (MgSO4) to bring up Mg? I think some of the hobby Mg additives may also be mainly MgSO4. For people doing a 1100 to 1400 Mg bump with epsom salts, you could be getting a dramatic rise (44%) in SO4 levels. Magnesium Supplements, RH Farley
 
I would say if you only use epsom salt that sulfate would be a concern. I've never used it for that reason. I've used ESV liquid mag in the past. But will be trying out Magnesium Chloride in the future.
 
<a href=showthread.php?s=&postid=10516276#post10516276 target=_blank>Originally posted</a> by JB NY
I would say if you only use epsom salt that sulfate would be a concern. I've never used it for that reason. I've used ESV liquid mag in the past. But will be trying out Magnesium Chloride in the future.

Regular water changes help control the ionic imbalances caused by just using the Epsom salt. you run into the same issues with the use of just MgCl with it being the chloride ions that get imbalanced. the best is to mix 3 parts MgSO4 to 5 parts MgCl.
 
Great Thread! It reminded me to quit wasting my time trying to dose Alk and Calcium and concentrate on the Magnesium first. I order Kent Tech M by the gallon jugs! Does anyone else have good luck with Tech M or is there something else better out there?
 
<a href=showthread.php?s=&postid=10516457#post10516457 target=_blank>Originally posted</a> by JetCat USA
buying your own MgCl and MgSO4 is much cheaper long term if you have allot of water volume.

Thanks. I will have to re-read Randy's recipe and try to locate the ingredients locally as I know it will save me some money. I still have 2 gallons of Kent left, but with 500 gallons of water, it will go quick enough.
 
I am really new to all of this and learing day by day. This site is awesome! I understand Joe that you and many other keep the Alk a little lower and Ca a little higher - relatively speaking. Does anyone do the opposite? I seem to recall reading something about "farming" that recommended higher Alk (~12, and lower Ca ~320) for faster growth. It was possible that color may be sacraficed though. Anyone experience that? Does it make sense to do that a while for someone with lots of frags and then slowly transition to the inverse as the tank matures and colonies grow? I don't know, just a thought since this is a disussion I thought I'd throw it out there. I don't have enough experience to comment but hopefully some of you do.
 
JetCat, I had to hunt for the basis of your 3:5 MgSO4:MgCl ratio recommendation. Improved 2-Part Supplement Article; Farley: Recipe #1, Part 3A. But to get the desired final ion ratio (table 2), I think that you also have to be using the 2-part additives alone to keep Ca and carbonate up? If you are using limewater and a calcium reactor instead of the 2-part additives for Ca and carbonate, wouldn't you want to use a 1:10 MgSO4:MgCl ratio as Farley recommended in the origonal Mg supplementation article? I'm not clear on that point.

I'm off to YellowKnife Canada for 10 days and hope to catch a fish or two. I hope you guys keep this up.
 
<a href=showthread.php?s=&postid=10516325#post10516325 target=_blank>Originally posted</a> by JetCat USA
you run into the same issues with the use of just MgCl with it being the chloride ions that get imbalanced.

:( What does a choride imbalance do? I thought the ESV liquid Mg was magnesium choride.

<a href=showthread.php?s=&postid=10516752#post10516752 target=_blank>Originally posted</a> by IPT
I seem to recall reading something about "farming" that recommended higher Alk (~12, and lower Ca ~320) for faster growth.

I don't think that would work. Higher Ca almost always equals higher growth. Acros in my tank grew like grazy with high Ca. with my Ca at 500 and Alk at 8 dKH I was able to pull a good 30 frags (min size 1 1/2") a month out of my 180.
 
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