Calcium Inhibits Coral Growth

[mojoreef]

I figured we would start a new thread so we wouldnt screw up the poll thread it started it. Anyway here it is

My post.

I dont know about lame but its the short and simple answer to the question. Calcium Inhibits (stops, will not allow, and so on) the growth of corals...any corals.....and yes this means all us SPS junkies to . Thus running high levels of calcium doesnt make sence..well at least to me.

Dons post

Why? Everyone nowdays runs high calcium. They just jack up Alk and MG to balance things out. So how is this inhibiting growth.

Don balance plays a role but it doesnt stop the fact that calcium stops a coral from growing, or in better terms it Inhibits it, as in a coral will not be able to perform their basic form of growth if calcium is present. Running high levels of calcium works against the corals growth sequence and makes it a huge energy budget hit. Why folks do it, I am not sure? perhaps they we told? not sure

Krish

Too much calcium inhibits and too little prohibits, thus the reason to have the right levels and right balance.

Inhibit and prohibit are the same thing actually let me put it this way 0 calcium=growth, any level of calcium=no growth. Does that muddy up the waters a bit for ya??

MOjo

 

[Krish]

Not going on the inhibiting growth factor, but wouldn't this just be a total waste to jack up alk and mag to balance out high levels of calcium?? In addition to that, do people actually do this in cases where they can't get their calcium levels to drop to what is considered the right range? Just jack up alk and mag?

Of course they do. As this poll show folks use elevated CA on a regular basis with the assumption that they just need to keep the balance. Obviously I was just egging Mojo to get this thread going. I'll quote Mike since Ive always liked his marble explanation.

"Ok one more time, lol here is a simplier way of looking at your water chemistry. SW is made of of many different element, the total of all those elements is what makes your salinity. So if you salinity is at 35ppt (or 1.025-6) its telling you that you have 35000 element parts in your SW.
So view your SW as a bucket and your elements as marbles. Your bucket can hold only 35000 marbles if your salinity is 35ppt, no more or no less. Each marble is a different color and represents a different element. SO thier would be 10810 sodium marbles and 19500 chloride marbles and so on and so on. All of these elements that are in the bucket make up the buckets size. If you add more then what is the balanced ammount only tw things can happen. One is that your salinity (or bucket size) will increase or the other is that some marbles that are already in the bucket will come out and the salinity will be the same.
This is very important when trying to make sure you have the right level of elements in your tank. A lot of folks have thier levels set but do not take the salinity into the equation, and it is critical.Calcium, magnesium and alkalinity are of major concern to us and are the elements that get used the most in our tanks so let look at them.
At nsw salinity of 35ppt or 1.025-6 calcium is balanced at 415ppm, magnesium at 1290 and a alkalinity level of 2.5meq or 7-8dkh.
Now if you run your tank at a lower salinity the ammount of elelments the sw can hold will go down exponentically. So lets say some one runs their salinity at 1.023 or 30ppt. your bucket is smaller so you can only have 30000 marbles in it, all your elements in that bucket would be reduced by 14 %, so cal would be 354, mag would be 1101 and alk would be affected the same way. Each point you drop will reduce your element levels by 3.5 %.
So here is a example of a person that thinks thier fine but isnt.
They run thier salinity at 1.023 and has a calcium level of 450 and alk of 11. Now they might think hey 450 is a good number and the alk is in balance. But when you look at thier salinity level they are at the point of saturation and poisening. This persons level if thier salinity was 1.025-6 would be, calcium = 513 and alk at god knows what. So when your looking or the sweet spot make sure you base it on the salinity you have your tank on.

And for those that think elevated calcium levels are a good thing for corals, remember that calcium inhibits coral growth. And will eventually stress out and kill your corals."

Just bringing over the rest. Let's discuss this a bit. Never knew any of this before as I'm sure many other don't either.

 

[Krish]

On the inhibiting growth, is this because when you typically have elevated levels of calcium the balance is usually out of whack between alk and mag and that's what inhibits the growth or is it something different?

 

[mojoreef]

No Krish that is what most folks tend to believe. Balance has an indirect effect but its the presence of calcium PERIOD that inhibits the growth.

 

[mojoreef]

Actually their are other things that will inhibit also, but they are related to the calcium thing to. I just didnt want to over simplify

 

[DonW]

On the inhibiting growth, is this because when you typically have elevated levels of calcium the balance is usually out of whack between alk and mag and that's what inhibits the growth or is it something different?

Your thinking water chemistry. Think coral biology and how its impacted by water chemistry.

Don

 

[returnofsid]

For a long time, I didn't understand this and couldn't wrap my head around it. Finally, one day, Boomer and Charlie explained it to me, in a way that made sense.

Calcium allows Stony Corals to build skeletons, AS a waste product. Stony corals have to rid their bodies of Calcium, and in doing so, build skeletons. However, they have to actually WORK at ridding their body of Calcium, using energy. If the Calcium levels are too high, the coral uses too much energy, to rid the calcium from their bodies. Think of is as being CONSTIPATED...LOL.

Funny as it sounds, "Constipated," was the key word, that helped me to understand the whole concept.

When, we, as humans, are constipated....well....we have to work a bit harder, using more energy....

When corals have to work harder, and use more energy, they have less energy that they can direct towards growth and health. So, when we unnaturally elevate Calcium levels, we're actually "constipating" our Stony Corals, requiring them to work harder, to excrete the elevated levels of Calcium, from their systems.

 

[TJL]

Mojo I'm all ears or eyes, please give us more on this. This will probably explain my near crash last spring just after going back to a mixed reef with a majority being SPS. I started dosing again and quickly had my element balance get out of whack. Because I had decades of reefkeeping experience I assumed that I would be able to wing it in increasing dosing at the same rate of adding SPS to the system. As anyone can guess, when you assume something it usually bites you in that proverbal ass. I was fortunate that because of experience was able to see the signs/my faults and do all the appropriate water testing then adjust accordingly. My knowledge of water chemistry is adequate in most cases but would really like to put more emphasis on this part of Marine Aquaria Husbandry.

Todd

 

[mojoreef]

Yea thats pretty close Sid and a good way of explaining it. Heres the skinny

All corals growth through the process of cell division, this is how they grow tissue. In the case of SPS, the coral is the layer of tissue over top of what folks call their skeliton. Its about 2 layers thick. Now the parameters with in the coral cell are the same as the water that surrounds them, as in level of cal,alk,phos, mg and so on.
The presence of calcium with in the cell will stop the cell from division so calcium=no division=no growth. Through evolution the coral has adapted by having a sort of pump with in it, now it gets complex here so I am not going to expand to deep unless required, but what happens is that the coral cell moves the calcium ion to the cell wall, from here it gets attached. Between the coral tissue and the skeliton is what we could call channels (for sake of simplicity) the channels allow water to travel through, now since this water contains alk, the alk ion with in the water draws the calcium ion from the cell wall (thus removing it) and ten looks for a clean surface to seed to. That surface is the skeliton and thus the skeliton gets bigger. Now with the calcium removed from the cell through this process the cell can now devide and thus we have growth!!

Ok taking it a bit deeper. The process discribed above is the basic biological process of coral growth and like every other process a coral does (attack, defend, photosyn, and so on) comes out of a corals energy budget which is at best very limited. So when you increase your calcuim level your making the process a lot more intencive to the coral and thus taking up alot more of the budget that could/should be used to do more critical process, the one that comes to mind the most is the ability to fight off pathagens/or survive events and so on. Thats why you hear a lot of "Wow man my corals were putting on 1 inch a month of growth and everything was just smokin!!! and then all of a sudden everything croaked for no reason???WTF???' type of comment

 

[mojoreef]

Ok so now other elements and the balance thing. As most of us know all elements with in SW have a direct effect on themselves and other elements with in the SW. SO how does that relate to the above mentioned???

Well we no the MG has an effect of alk right, it binds it and does not allow the alk to attach the calcium ion and then percipatate out of solution. So if we ran high levels of MG what would the effect be with i the coral and thus its ability to grow??

Alk now will attract calcium ions and thus look for a way to percipatate, so how will this effect??

Then their comes the phosphate thing and that one has a huge effect on how both calcium and alk reactes/binds/percipatates and so on in the tank, it has even a bigger effect on that whole thing works with in the coral itself.

Mojo

 

[Frankie]

Great topic.
Good points on why our goal is to have our aquariums as close to NSW as possible.
Again I am disappointed in no mention of K+ element (potassium) playing a major role in coral growth.
I think this is a commonly over seen element in water chemistry needed for the growth of stoney corals.
Like Ca++, K+ also needs to be maintained at levels between 380-410 mg/l. for proper coral growth and plays a major part in tissue color.

Frank

 

[mojoreef]

Again I am disappointed in no mention of K+ element (potassium) playing a major role in coral growth.

Step up son :lol: its an open forum, it would be great to have lots of folks particapate, it how we all learn.

Like Ca++, K+ also needs to be maintained at levels between 380-410 mg/l. for proper coral growth and plays a major part in tissue color.

Tell me about this Frankie

 

[Krish]

Well, finally the advanced forum gets a much needed bump! Thanks Sid and Mojo on the info/clarification on calcium. I know Don had the answers as well, but he looked like he wanted us to fish for it a bit first . With that said, it just goes to show how much there is to really learn about the hobby. I never imagined things worked like the way it was described here...

 

[Boomer]

Boy is this thread a can of worms

Why folks do it, I am not sure? perhaps they we told? not sure

As people "think", more means better = more growth and I have always said no and recent data says so.


balance plays a role but it doesnt stop the fact that calcium stops a coral from growing


Where did this come from Coral grow is at pretty much the same rate from 360 ppm to 500 ppm Ca++. The issue is high Ca++ is not needed. It is more on the Ca/Mg ratio, its Alk and pH. When one sees coral growth or coral growth reduction it is NOT just a Ca++ issue, it is a set of multi-complex issue, as a function of coral biology and solution /coral chemistry kinetics.

Well we no the MG has an effect of alk right, it binds it and does not allow the alk to attach the calcium ion and then precipitate out of solution. So if we ran high levels of MG what would the effect be with i the coral and thus its ability to grow??

Low Mg++, increases abiotic precip of CaCO3 which is not the same thing as biotic to a degree but see below. Normal levels of Mg++ act as a protective inhibitor for abitoic precip of CaCO3 as it "poisons" the surface slowing down CaCO3 precip. This is not a coral.



Mg++ has about nothing to do with coral growth /say for us. It is just a substitute ion for Ca++, as it is there in seawater, just as Sr is, which substitutes for Ca++ in Aragonite. Furthermore, Mg++ does not fit into a Aragonite crystal lattice. However, in most hard colors there, is some Hi-Mg++ Calcite and even Lo-Mg Calcite growth sites within the the coral skeleton along with the mostly Aragonite skeleton.


Maybe me needs to bring my adopted son here Chis Jury to explain all, as his field is coal growth biology and its kinetics as a function of Ca++, Mg++, pH and Alk. Some things he has mentioned in a question on this subject of Mg++.

Above a molar Mg/Ca ratio of ~2 in sea water we have an aragonite nucleation field for abiotic precipitates. Hi-Mg calcite can also form though. A ratio of 1-2 favors hi-Mg calcite, while ~1 or less yields a low-Mg calcite nucleation field (again, for abiotic precipitates). Organisms can deviate from that a bit, but their calcification is influenced by variation in seawater chemistry (some more, some less). Ries has done some really spectacular work on this in the last several years. I've uploaded two of those papers (Ries, 2004; Ries et al., 2006) to the PDF library. Ries et al., (2006) is the one most applicable here, but some methods are referenced that are explained in Ries (2004).

I'm going to guesstimate that the Ca++ concentration is probably somewhere in the neighborhood of 400-500 ppm. With a molecular weight of 40.08, that means 9.98-12.48 mmol/kg Ca++. Mg++ has a molecular weight of 24.30, so that's 28.8 mmol/kg Mg++. For 400 ppm Ca++ we have a Mg/Ca ratio of 2.89. For 500 ppm Ca++ we have a Mg/Ca ratio of 2.31.

Ries et al., (2006) tested the effects of a Mg/Ca ratio of 1.0, 1.5, 2.5, 3.5, and 5.2--spanning the range from the Cretaceous to today's sea water. To make the ratios go down ionic strength was held constant while calcium concentration was increased and magnesium reduced so as to achieve the desired ratio (Ries, 2004). They used 3 coral species: Acropora cervicornis, Montipora digitata, and Porites cylindrica. As the Mg/Ca ratio dropped from modern to ancient chemistries all the corals started to produce a mixture of aragonite and calcite, and the Mg content of the calcite was proportional to that in the sea water. At the lowest Mg/Ca ratio of 1.0 the corals were all producing ~1/3 of their skeletons as low-Mg calcite.

They also measured rates of calcification. The M. digitata actually performed best in the Mg/Ca ratio of 3.5 with 2.5 coming in second. They grew slowest in 'modern' sea water (5.2), 'Cretaceous' sea water (1.0) and 'early Cenozoic' sea water (1.5), though I wonder if at least the decrease in modern sea water might be related to the absolute Ca++ concentration more than the Mg/Ca ratio. In any event, the other two corals (A. cervicornis and P. cylindrica) both grew equally well with a 5.2 and 3.5 ratio. P. cylindrica did well in 2.5 as well, but A. cervicornis dropped off quite a bit. Neither A. cervicornis nor P. cylindrica did particularly well in the 1.5 and 1.0 Mg/Ca ratios.

As above, I don't think the 2.3-2.9 ratio that we probably have here is enough to reduce calcification for the Montipora, but it could be, or it could be getting pretty close. It may well be enough to reduce calcification for some corals though. Most likely this reduction has something to do with reduced ability to induce nucleation of the preferred polymorph by the corals (i.e., they're somehow equipped to produce aragonite and calcite crystals keep nucleating), but who really knows at this point?

All please read this thread. It is really the pH and Alk that is "the" thing kinda. In short, if one keeps All at or near NSW and just increases the Alk there will/may be better coral growth and some studies have show this.

Chris Jury/MCsaxmaster article on calcification! - Reef Central Online Community

 

[mojoreef]

Ok first off no three foot long posts are allowed!!!! And second what do you know about biology, your a chemist!! LOL ok that was a joke and I am running for cover!! Ok I will go back and read your really long post.

MOjo

 

[Boomer]

Like Ca++, K+ also needs to be maintained at levels between 380-410 mg/l. for proper coral growth and plays a major part in tissue color.

Growth no so IMHO. This is mostly, as are others ions a Zeovit thing, that gives colors that a reefer likes/ wants, not that the coral needs them at all. Coral do not need them, other than at least acceptable usable levels.

 

[Boomer]

Umm Mojo, I double majored in Zoology/Biology and Geology just to get things straight Most of my chem is self-taught, as when I stated in this hobby, back in Cretaceous times, nobody looked a chem :lol:

 

[mojoreef]

Where did this come from Coral grow is at pretty much the same rate from 360 ppm to 500 ppm Ca++. The issue is high Ca++ is not needed. It is more on the Ca/Mg ratio, its Alk and pH. When one sees coral growth or coral growth reduction it is NOT just a Ca++ issue, it is a set of multi-complex issue, as a function of coral biology and solution /coral chemistry kinetics.

Yes but the fact remains correct?? the cell can not devide in the presence of calcium with in it? and cell devision is growth correct? And in the case of SPS who can see growth anyways??

Low Mg++, increases abiotic precip of CaCO3 which is not the same thing as biotic to a degree but see below. Normal levels of Mg++ act as a protective inhibitor for abitoic precip of CaCO3 as it "poisons" the surface slowing down CaCO3 precip. This is not a coral.

Well thats what I said in human speak

Mg++ has about nothing to do with coral growth /say for us. It is just a substitute ion for Ca++, as it is there in seawater, just as Sr is, which substitutes for Ca++ in Aragonite. Furthermore, Mg++ does not fit into a Aragonite crystal lattice. However, in most hard colors there, is some Hi-Mg++ Calcite and even Lo-Mg Calcite growth sites within the the coral skeleton along with the mostly Aragonite skeleton.

Sure it does. We are not talking about NSW we are talking about what folks seem to be running in their tanks, which in alot of cases is a long way from NSW. Also dont most these MG/Sr replacements evetually become replaced themselves??

Maybe me needs to bring my adopted son here Chis Jury to explain all, as his field is coal growth biology and its kinetics as a function of Ca++, Mg++, pH and Alk. Some things he has mentioned in a question on this subject of Mg++.

Afraid of doing the leg work are we, hehehe Ok how long do I have to run until it goes off??? lol

Ok thats enough for this post, I will wait for the reply. Oh and DON stop sitting on the sidelines snickering and get your butt in here. lol

 

[Frankie]

Thats just the point Mike. There is very little information on the effects of potassium and the role it plays with Calcium and Magnesium. Randy refers to Ron Shimek on this topic and understanding this article is a bit dizzying. would be great to have some of this broken down into layman's terms. (in my case, mention a hammer once and a while )
It's (In) The Water by Ronald L. Shimek, Ph.D. - Reefkeeping.com
It is obvious though from his table that K+ is a major player and needs to be inline with the rest to get something even remotely close to NSW and even he states that our aquarium water is very far from being close to NSW in any other way other then "being wet" LOL
After getting into this probiotic method K+ seems to be the leading element being depleted from the water. More so a problem then Ca++ losses in a heavy stocked established reef. there are debates on what is causing this, from what is being told the element is not reoccurring like Ca++ and Mg. but actually being removed from the water.
Now there are people leaning more towards the skimmer process being the culprit though I have my doubts.
I think it is more then likely the bacteria that uses it up. Randy talked a bit about this in another thread a few years ago when the probiotics were just getting popular. I think it was boomer who started the ruckus in that thread.

I have been following an aquarium where the user is pushing his potassium levels pasts NSW levels and seeing greater growth from from high levels. I would like to learn more about this.

I see boomer posted so I will go back and read.
Frank

 

[Frankie]

I see boomer posted so I will go back and read.
Frank

Oh boy~