Question 1, Calcium
 

Please read http://www.canreef.com/vbulletin/showthread.php?t=23994 to see where this thread is going.

Ok I thought I would start off with probably one of the most monitored elements to all of us... Calcium.

why is it important, how do we maintain it, and why do we try to push for higher levels than NSW even though it slows down coral growth? Or for that matter what level should we be aiming for.

well this should start up some good conversation lets keep it clean and learn.

Steve

Steve,

I have never read that higher levels of Ca than NSW slows coral growth. Can you provide a quote and source for this statement? TIA :smile:

According to.....

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

Back to your question.....

I do not, and never will, use Ca or other reactors to maintain Ca or other reef chemistry levels. Instead, I drip kalk into our reefs every night to help maintain Ca and alk levels. Then, once every 10-20 days, I test for alk, Ca and Mg, record dates of test results and how much I adjust, and adjust all levels at the same time. Sometimes, if the halimeda in each reef is looking a bit ragged, without testing, I will adjust and record how much I add of Ca, alk and Mg in each reef. I use data recorded from previous test results to ballpark the amount of each chemistry component I adjust without testing.

I know you just asked about Ca, but I don't feel right about just talking about Ca when I do the whole shebang at once. If I were to separate the Ca portion of the three components I test and adjust, I would have to reply that I keep Ca levels between 400 to 450 ppm. I also initially aim for higher alk and Mg levels when I test and adjust the chemistry in our reefs. The higher levels of Ca, alk (10 to 12 dKH), and Mg (1300 to 1350 ppm) are in our reefs so they can be slowly utilized by corals, coralline algae, calciferous macroalgae, etc.

I don't know if what I have just described is a useful way to work with Ca and other chemical components in a reef system. Short of testing and adjusting all components weekly, which probably isn't going to happen, this is the best I believe we are going to have in our reefs.

Hope my comments help the discussion begin :smile:

reply
 

IMO there are two reasons why people aim for highter calcium levels.

1. Add the calcium to a higher point so that they don't have to do it as often.

2. They believe that it is better for the corals.

My question is; do corals actually get used to higher calcium levels and develop a higher appitite for it over time?

I aim for 380-420ppm calcium, and have begun to feed my corals phyto to give them the little bit extra. I use Kent turbo calcium and dose Kalk weekly to because it seems to buffer my water better. I went through a faze during the winter where I tried every kind of Calcium additive (except reactor) and found that turbo calium was the best to use. It is by far the most concentrated of all additives on the market.

I'm guessing that raising Calcium to overly high levels must result in overly low Alk levels since there's an inverse relationship between the 2. So I assume coral growth slows for that reason.

http://www.advancedaquarist.com/issues/nov2002/chem.htm

"If, for example, you add too much of a calcium supplement, you will drive down alkalinity as you get precipitation of calcium carbonate in the tank. Likewise, adding too much of an alkalinity supplement can result in reduction of calcium. "


I wonder if adding aragonite to my top off water reservoir has any benefit. The fresh water is low in PH and should very very slowly dissolve the aragonite and add calcium and alk into the top off water.

Really depends on the coral, it's not a generalized answer. Only scleractinians will be a concern and of those, only "SPS" are really a factor. Euphyllia, Faviids and the like are so slow growing to begin with that elevations above NSW values will not make much of a difference.

When it comes to "SPS' in particular, the problem is they have a specific level that they strive for, loosely being 410-420 ppm to keep equilibrium with their cells. The coral is constantly depositing the Ca it takes in to rid itself of it. When the level of Ca is artificially raised above that, the coral has to work harder to deposit more Ca. In doing so, it cannot easily match the rate of skelatal growth to tissue growth which is where the stress comes in. More commonly a tank running very smoothly will not have much if (m)any issues except for thin reedy growth. Due to the continual stress of the higher Ca, any upset can easily cause a stress event in the coral it would otherwise be able to deal with. If the higher Ca uses up much of it's already low reserves of energy, there's nothing left when a stress event (temp, pH, salinity etc) comes into play.

http://www.findarticles.com/p/articl...02/ai_n8850134

http://jeb.biologists.org/cgi/content/full/205/14/2107

http://www.advancedaquarist.com/issu...2004/media.htm

http://aslo.org/phd/disccrs/200206-4.html

Cheers
Steve

Sam,

Reading a little further into the article you posted, I found .....

http://www.advancedaquarist.com/issues/nov2002/chem.htm

So if I go by what the ranges are, I'd be a bit high going to 12 dKH in alk, but it shouldn't pose too much of a problem. At least according to the quote.

Yeah, keeping it within the ranges is good. The problem is when Calcium is overly higher than NSW as what I assumed Steve meant. I don't mean 420-450 range but more like something over 500. In that case, Alk would be overly low. Thus slowing coral growth I assume.

not a problem Bev, this is the kind of reasoning and spreading I was hoping to see, related and still on topic but expanding the discussion.

Ok for me to explain the coral Ca thing it would take me a hour.. but I can quote and friend used to be on the board as "powerreef" and all I can remember is his first name, Mike. anyways he sums it up really nice and if you want more deep I am sure I can find it but here it is.
(oh and Steve-s is on track)

"Calcium will actually inhibit the molecules in the coral tissue from growing. Since the coral polyp is always pumping in fresh SW the calcium concentration in the surrounding water is the same as it is inside the molecules of the coral. In order for the molecule to survive and multiply it must lower the concentration of calcium with in it. It does this by attaching the free calcium ion to its outer membrane and then secretes it out and forms the skeleton. So the calcium is a waste product in sense. the real player on growth is the carbonate and the reaction it has with CO2 the zoox releases.
So having any level of calcium in your water that is beyond normal balanced levels creates a huge energy loss the coral has to give up in order to free itself."

So from a few months of reading and following stuff like this I personally aim for ~380ppm for my Ca level.

Some one was talking about Alk, I think it was Bev again.. I always keep mine at 13dkh, my softies, LPS and SPS all exhibit more intense coloration when it is at this level and I personally have never seen a bad effect of it.

Steve

nope I was thinking anything over 400ppm, now how much difference will 400 to 420 make?? I don't know it may be a mm every 6 months. I try to keep mine under 400 and 380 is the target.


Let me explain something first, the Ca levels I am talking about are going to depend on your Salinity also.. there is a balance for salinity VS Ca. for example if your salinity is 1.027 then your Ca should be 415ppm for the balance, higher than this and you are in the zone of diminishing returns, if your salinity is 1.023 then you are probably looking at about 360ppm for a ballanced Ca level, so if you keep the tank at 1.025 then you might want to be aiming for about 390ppm Ca


Steve

Yup, that's what I meant in general, Ca should not actually exceed 420 ppm but in reality, the coral begins feeling stress (working harder?) at the 410-415 mark. Personally I keep mine between 400-410 ppm as a rule.


Your in the right place, just might want to use a different designation. If keeping your water at 35 ppt, Ca should be 415 ppm. When you reduce the salinity by say 30 ppt, you've diluted the chemistry overall by 15% (30,000/35,000). Typically why some have problem maintaining target levels to begin with. So the 415 ppm would also be reduced by 15% giving you a value of 352.75 ppm. Same explaination, just different route to get there. :razz:

Cheers
Steve

ya I think I had 357ppm or something.. just rounded up to 360:mrgreen:

Steve

I certainly don't profess to understand the whole chemistry thing that goes on in my tanks but I do know through trial and error and doing a whack of research what works for me and at what levels my tanks seems to do their best. I try to maintain my aquariums calcium between 420 and 440, my Mg. at 1300 to 1350 and my KH at 6.5 to 7.5. Salinity between 33 and 35ppt. I run a calcium reactor on my 2 large systems and I would highly reccommend running this piece of equipment on any larger system that you plan on keeping calcium demanding species in. I am going to try adding some magnesium granules to my reactor media next time I have to add some to see if this will eliminate the need to dose mg. On my 44g cube I do dose C-Balance 2 part solution but I find this a PITA to stay on top of and not have swings in levels. If I do find my calcium dropping (which has not happened since I brought the reactors on line) I have some Kent turbo calcium that I plan on using.
I agree with Bev that it is difficult to talk about Calcium without also discussing the balance of KH and Mg as they are all related and integral to each other.

Do you have a Mg drop whith the Ca reactor running? I found once I did my inital corection the Ca reactor maintained Mg also. what are these Mg crystals you are talking about?

Steve

I still find that I have to dose Mg. every once in a while as mine will creep down below 1300. I have been using the Seachem Mg. but here is a link to a page that lists what I bought (it is the granules)
http://www.captiveoceans.com/product...pplements.html
Here is what it says about them:
ZEOmag is a pure magnesium granulate to be used in calcium reactors (5-15% of total media volume) to maintain magnesium levels. Magnesium is easily added without chloride and without disturbing the ionic balance in your tank. Granulate size 6-12 mm.
The tank that I have to dose the most often is my cube tank that does not have a reactor hooked up (yet). What I usually do is just add Mg. to my change water to bring the level up to just over 1400 in that water and it seems to keep things fairly steady in my tank.
I think that the most advantageous thing about a calcium reactor is that it keeps your levels steady and consistent and balanced and not constantly changing the way they have a tendency to do unless you are super diligent in adding exactly the right amount of 2 part or other solution.

I have used Kent's Liquid Reactor for my tanks for 2 years now & it's done a great job growing my clams especially. Ask any of the local reefers who've seen my Squamosa or Derasa (before it's mantle got torn from a shift in current) & they'll attest to the very high growth rates in my tanks. I don't have a calcium reactor, but then again, I'm not sps-heavy in my tanks. Yes, I have to dose frequently (daily or every other day) but I look at my tanks bazillion times a day anyways, so it's part of my night time routine to add the Liquid Reactor.

That being said, having seen Props, Chin Lee's, Jack's & TomR's tanks, if went really big or heavy into sps, then I would also invest in a Calcium reactor for the ease & stability it offers.

Good idea on these discussion threads, btw.

Anthony

Interesting, I think there is a little misleading info in that sales add though. Pure Mg is a soft metal that is very flammable so what they are selling isn't pure Mg :mrgreen: But I wonder what else you are getting with it? It looks like it might be good to try although it is expensive, I would be looking at 50.00 to add 15% of my reactor media..

Steve

Compared to some other things that I buy for my aquariums $50 doesn't seem that bad and as I understand it the 15% will last as long as the reactor media so in my experience at least 6-8 months. I suspect that it is probably some kind of dolomite (I think that is what it is called) material. I'm going to put it in my reactor on my 230g because I have to add new media to that in the next month and on my 190g it looks like I will be another 6 months or so before I have to add any media so it will give me a chance to monitor if it makes a difference.

In any article I've read (eg. http://www.advancedaquarist.com/2005/12/aafeature1 ) the Ca for NSW is generally referred to as 410 - 420 ppm. Evolution being what it is, why would we shoot for anything outside this range?

because the average Ca in NSW is 400 . it varies a little in various parts of the world. I think reefers have inflated the numbers over the years thinking it is better. so if we look at the average we could easily guess that maybe we should be looking for 380 to 420. but there is also something else we should be looking at, Mg? nope it won't cause a problem or difference in Ca unless it is low (and that isn't from some book:redface: ) but Alk, Alk will allow your Ca to either go above normal, hold it at normal or let it dip below normal depending on its concentration. personally I don't know of any reef tanks that are perfectly balanced. I used to go for the higher Ca thinking well if 400 is good 450 must be better:mrgreen: but found it wasn't over the years. I have found the chemistry that work the best for me is a Ca of about 380 and a Alk of about 13. now this is just my findings others might find different levels, but I think the "well if 400 is good 450 must be better" attitude has been creeping levels up for years.

Steve

I have been guilty of the same thing as Steve - if 400 is good then 450 must be better and 500........whoo hoo. My experience has shown me that if I shoot for calcium in the 400ppm range and Alk/DKH in the 8.5 range I seem to have the most success.

-calcium?
 

-i really didn't research calcium too much and know fairly little, and was wondering if there is any reason why calcium levels could be 2 high, not that it happened 2 me but just wondering, also is there such thing as too high calcium levels?

Its not quite that simple, and to give you a real answer we need to know more info, ie. salinity, alk ect.. even type of test kit.

usaly a high Ca corasponds with a low alk but there are always exceptions.

Steve

Yes. Anything over 420-425 ppm is way to high of a calcium level. Corals need calcium to survive especially SPS.

ok your confusing me with the wording of your reply, the two sentences, kinda contradict each other.

anyways I didn't answer your last question about can it be to high. depends what you are after. anything over 380 to 400 to me is a waist of money and time, but if you have a tank that sits at 440 and all your other levels are fine and your happy with growth, ect... then why fight it.

with my tank I found I could run 1/2 the co2 to maintain the Ca level at 380 as compared to when I ran it at 420, so this would also translate to less reactor media also. and even though I was using less media I was getting faster growth. also the lower Ca let me push my alk up to 13 which made my colors simply amazing.

the only situation I think that would be immediately harmful "to high" would be that if you had your Ca level so high that it forced your alk way to low as they work opposite, if your a little to high it may have long term effects from stress but there are so many variables that it would be hard to prove.

Steve

haha
 

-it's true he phrased it like an opposing and contradictory sentence lmao

Mik just likes to post useless comments on every thread he/she can.

Its true. lol

ya
 

-sounds about right from what i read

calcium
 

-it's my first week of cycling and all i got in my 33-gallon is 4-chromis
20 pounds of live rock,fiji,tonga,and jakarta and an active little softie
and my friend came over and we tested my calcium level @ 480 and I
was wondering if it's 2 much, cuz i know if theres excess calcium that
it precipitates, so 2 much, good enuf or perfect??

reply
 

Have you added Ca suppliment to your water? 480 seems too high to be coming from just your salt. What salt are you using?

Live rock shouldn't contribute to you CA, should it?

420 ppm is the ideal calsium for reef tank.

-purple up
 

-well all i added
was 1 capful of purple up which is ionic calcium but i didn't think it wud cause
that much of a calcium spike!

reply
 

I'll have to look into Purple up then, it seems quite potent.

potent!
 

-potent is right, it's 1 capful for 50 gallons so when i put a capful for my
33-gallon as u can imagine it made a difference! honestly doesn't cloud up ur
water like others, @ least not for 2 long. -andexpect 2 get some white film on
all sides of ur tank from the calcium. it's actually made specifically for coralline algae growth.

come on now, have you even read this thread or you just making stuff up?

Steve

ya well...
 

-420 iz good but mines still @ 470 ppm :neutral:

and I am still waiting to hear what your Alk is. if your Alk is fine, then you are not harming anything and you can just stop adding Ca suplements untill your levels are back to normal. as a new tank cycles, you will also have a Mg drop so keep an eye on that also.

Steve

I run my tanks at 1400ppm Magnesium 10-11 dkh and between 400-420ppm Calcium. The tank seems to be consistantly around 8.0 to 8.3 ph without any interference by me. I have only been in the hobby for about a year but this is what has been working well for me so far.

The perfect levels are going to vary from system to system. From what I have read a certain calcium/alkalinity balance will be most useable by the corals for calcification at a certain ph. Sometimes higher then 8.3, sometimes lower, depending on how high or low the alkalalinity/calcium levels are. I hope that statement makes sense.

Question
 

Ok, I have been reading this thread and have another question to ask. What equipment does everybody use to test their Ca and Mg? I have been told that the cheaper test kits are not very accurate. So What is the best most cost efficient test equipment for the average reefer?

Hey everyone. I'm a newbe here and very interested in the dicussion. So if I understand well, with my parameters at; salinity 1.026,calcium 480,alk 13 I would be doing more harm than good? Every thing looks OK in there. I'm not getting the growth that I've been expecting but colors are nice and nothing is deteriorating. I'm dripping kalk 24/7 via timed kalkwasser and dossing calcium and magnesium via dual chamber reactor, PH fluctuates between 8.1 and 8.4 nihgt to day. Would it be more efficient another way?