Calcium vampires...

[Sk8r]

I'm going to repost this from an answer to another thread, because it's real important to understand.

When you get a stony coral (a coral with a hard skeleton) or a clam, you have to keep your magnesium, alkalinity, and calcium levels up or it can impact the whole tank in a way you won't see happening (unless you test weekly) ... until things have gotten strange and bad.

Scenario. You buy a little stony coral or two. They come in 'asleep' quite often. Or they sit and soak up light because light helps them make sugar, and they live off that, but not forever. When they're full of energy they start sucking up the calcium from your water...and strange things ensue.

The calcium/alk level will hold steady until the magnesium falls below 1200...and then that level will trend down.
If the calcium falls down below 420, eventually snail shells start dissolving and fish no longer get the calcium they need for bone and muscle. Think of stony coral as 'calcium vampires'---their sucking it up forces your water constantly to dissolve more calcium to saturate the water, and that mg/alk balance is what adjusts the water ph to be ABLE to dissolve more out of lime and rock and sand. I've seen tanks where the snail shells had turned to paper and it was a wonder the fish were alive, because of that extreme calcium shortage. Had it gone on, everything would have died.

I had about 4 small stonies in a 50 gallon tank---chiefest, a three-head hammer, and, being aware what they need, I started supplementing a teaspoon of calcium. They started feeding in earnest, and were sucking down 2 teaspoons of expensive calcium supplement a day---this got crazy-making and expensive. So I went over to limewater, so that 5.00 worth of lime does the job for months, as long as I keep that mg up. As long as the mg is 1300 or more, the buffer holds up fine [the alk], and the limewater just keeps everything stony, shelled, or fishy very happy and healthy. Because all that is in good balance, I also maintain a very, very steady alk, which means all my fish have really healthy slime coats, and this (coupled with not letting parasites into my tank) gives them good health and a natural resistence to parasites and disease.

Within about 4 years, that three-head hammer had more than 100 heads, was the size of a basketball and was multiplying exponentially. When I fragged it and spread it out, the tank looked like a Rose Parade float.

If you set up for stony by having that supplementation going early, you'll find that healthy stony and clams open faster and start growing.

 

[myofibroblast]

Calcium vampires...

If the calcium falls down below 420, eventually snail shells start dissolving and fish no longer get the calcium they need for bone and muscle.

Are you suggesting calcium concentrations just under 420 ppm will significantly derange calcium homeostasis in marine fish? I am highly skeptical of this statement and perhaps you can clarify your statement for me.

1. Natural seawater, lets say 400-420ppm, is significantly hypercalcic compared to the composition calcium (both interstitial and intracellular Ca concentrations) of marine fish. For example, natural seawater has Ca concentration of about 10 mM, compared to marine fish "bodily fluid" or interstitial fluid which is around 1.5 mM, and intracellular fluid which is at 100 nano molar.

2. Marine fish thus maintain a homeostatic Ca concentration at around 1.5 mM DESPITE their calcium rich environment. Because marine fish ingest seawater, they require a mechanism of Ca excretion. This is done by renal excretion (we know that marine fish urinate urine containing divalent ions like calcium, mg, and sulfates) and likely by the gut.

3. Therefore, I am highly skeptical of your claim that calcium level dipping below 420ppm will result in a scenario where marine fish "no longer get the calcium they need for bone and muscle."

4. Even at calcium levels of, say 300 ppm, where stony corals may cease to incorporate calcium for skeletal growth, that level would represent excess calcium for the needs of marine fish. And my suspicion is that the regulatory mechanisms (through a balance absorption and excretion) will maintain calcium homeostasis in fish just fine.

5. And lastly, I'm uncertain if bones in teleost marine fish play a significant role in calcium homeostasis. If you have evidence that bone resorption or hypocalcemia occurs in marine fish living in aquatic environments where Ca is at, say 200-300 ppm I'd love to look at the literature. Again I doubt the literature exists as evidence and data would not support such a hypothesis.

It is critical to us who are learning the hobby to receive accurate information. The simplification where calcium homeostasis in marine fish and stony corals are lumped together presents a significant mistreatment of the subject. This may lead to unnecessary worry and expense when hobbyists play with divalent ion and carbonate chemistry where it is not warranted. More worrisome is that this statement may be repeated in other posts and hobbyists keeping marine fish only will start to "freak out" about their fish's skeletal health unnecessarily.

 

[DasCamel]

My alkalinity dropped in a scenario where corals were added, then after a month they sucked minerals dry. My Mg though stayed high. I do think its possible to have alk and ca drop with adequate Mg. I'm dosing Kalk daily with top off everything is looking great. testing regularly.

 

[coralsnaked]

SK8r
Join Date: Feb 2006
Location: Spokane WA
Posts: 25,125
Blog Entries: 27

myofibriblast
Join Date: Jul 2014
Posts: 74

You do the math on who prescribes good info on this site. It is easy enough to pick any post apart but more difficult to present a set of relative facts that present a needed set of parameters in a case study to describe a particular outcome to a set of individuals who are only interested in results of maintaining normal params on foundation elements and not calcium homeostasis in fish.

Most of us would perceive the notion that Sk8er was presenting. That the outcome of adding stony corals to your aquarium without adjusting for their precipitous appetites for calcium and the need to keep balanced the Alk and Mg with this consumption would eventually cause the depletion of Ca to a point where it would cause havoc on a reef system.

Possibly your rebuttal would be better suited for Scientific Monthly whose readers have possibly as sophisticated an intellect as yourself.

Thanks Sk8er I like many enjoy your posts. They have always been informative and helpful! Please feel free to embellish a little as it makes the story more interesting.

 

[myofibroblast]

Calcium vampires...

It is easy enough to pick any post apart but more difficult to present a set of relative facts that present a needed set of parameters in a case study to describe a particular outcome to a set of individuals who are only interested in results of maintaining normal params on foundation elements and not calcium homeostasis in fish.

You are most certainly entitled to your feelings on my posts and whether you care about the truth of information you receive. I have no further comment on that matter.

My thoughts:
1. Information can be exchanged in an easy, widely understandable manner. Sometimes this is done through simplification, sometimes through demonstration. But you can communicate this information in an easy-to-understand way without injecting misinformation or baseless claims.

2. While you may not care about the truthfulness (in distinction to usefulness) of the information presented here, some of us do. If the local fish store owner told me to maintain my calcium over 420 ppm or my fish will die from low calcium, I would have responded similarly. There is no reason to excuse misinformation presented here but not at the LFS. That is my opinion and you are very free to disagree.

3. For some of us, misinformation may have real financial consequences. Someone hearing their fish may die because their calcium is at 390 ppm may suffer undue mental stress, react in a way that may not be necessary, start dosing calcium and what not. This is the hazard where information is exchanged without responsibility.

4. Responsible individuals can accept disagreement and discuss errors without turning the exchange into an ego war. The original poster certainly contributes significantly (and in my view very positively) to the forum, but that doesn't mean we cannot discuss differences.

And finally, to your point that no one cares about calcium maintenance in fish, the entire purpose of the post is about declining calcium levels with stony coral addition, and the health impacts that result. As such, I would argue misinformation about calcium levels and fish health IS a significant issue.

Good luck.

 

[Sk8r]

Several things in our tanks prevent extreme loss of calcium, and usually the coral itself will die before it can get even so far as dissolving snail shells, but not always. The water will dissolve what is amenable to dissolution, and the fact that fish food with some calcium content is entering the tank from outside provides the fish some relief...so no, your fish are not going to dissolve, but by the time a tank gets that far off optimum it is usually going 'off' in more than one respect.
It's not uncommon for somebody to go out and invest heavily (for him) in corals the requirements of which he does not know, and then post a query as to why something is going wrong. Often by the time of the post, things have gone quite far toward damaging the coral. But now and again you find the tank where the depletion has gone farther than that, and the calcium deficiency has led to a general water quality issue...and bizarre problems a new hobbyist may not realize are connected.

 

[Mark9]

SK8r
Join Date: Feb 2006
Location: Spokane WA
Posts: 25,125
Blog Entries: 27

myofibriblast
Join Date: Jul 2014
Posts: 74

You do the math on who prescribes good info on this site. It is easy enough to pick any post apart but more difficult to present a set of relative facts that present a needed set of parameters in a case study to describe a particular outcome to a set of individuals who are only interested in results of maintaining normal params on foundation elements and not calcium homeostasis in fish.

Most of us would perceive the notion that Sk8er was presenting. That the outcome of adding stony corals to your aquarium without adjusting for their precipitous appetites for calcium and the need to keep balanced the Alk and Mg with this consumption would eventually cause the depletion of Ca to a point where it would cause havoc on a reef system.

Possibly your rebuttal would be better suited for Scientific Monthly whose readers have possibly as sophisticated an intellect as yourself.

Thanks Sk8er I like many enjoy your posts. They have always been informative and helpful! Please feel free to embellish a little as it makes the story more interesting.

Just because somebody has a 1000 or a million posts does not mean everybody has to agree with everything they say.
Attacking myofibriblast is not justified.
I don't agree with everything Sk8r says and i don't think anyone is correct 100% of the time.
Cut myofibriblast some slack, he voiced his opinion which he should be able to do.

I have many many corals and i did not have to dose anything, regular water changes kept my numbers just fine.
Once i got a clam, dosing became necessary as i didn't want to do a water change every 2 days.

 

[kurt_n]

A good buildup of coraline algae - even without corals - can even deplete calcium levels down to an unhealthy level. That happened in my tank when I just started out. Couldn't figure out why my coraline algae was dieing off. I didn't have corals yet, so why should I be checking calcium... right?!

As far as information shared on an internet forum about a hobby that few partake in, if you're looking for information that's been vetted by peers in the scientific community... you're looking in the wrong place. Sure, we should be as accurate as possible, but if that means you can't post unless you have a published scientific study to back it up, this place is going to be pretty quiet.

 

[myofibroblast]

...so no, your fish are not going to dissolve, but by the time a tank gets that far off optimum it is usually going 'off' in more than one respect.

Precisely. I favor leaving fish bones, muscles and hypocalcemia out of this, and focus on water quality (and how mineral depletion may affect water quality in general).

 

[myofibroblast]

Calcium vampires...

Sure, we should be as accurate as possible, but if that means you can't post unless you have a published scientific study to back it up, this place is going to be pretty quiet.

Freedom to post and willingness to discuss disagreements/differences need not be mutually exclusive. In fact, I think they go quite well together.

Best.

 

[gbru316]

Just as a reminder, this post is in the "New to the Hobby" subforum. Those entering the hobby probably don't have an initial interest in the biology behind the processes being discussed. As such, the original post was well-worded for the novice.

While certainly not a beginner, I really appreciate these posts from Sk8r. They're both informative and easy to read, and I assume they're a big help to those just starting out as the LFS is often not the most knowledgeable when it comes to aquarium care.

IMO, a deeper scientific discussion should be reserved for the "Advanced Topics." subforum. Sk8r knows the audience he writes these posts for, and nails it just about every time.

 

[myofibroblast]

Those entering the hobby probably don't have an initial interest in the biology behind the processes being discussed.

Sk8r knows the audience he writes these posts for, and nails it just about every time.

And as further reminder:

1. Novices like myself may have an interest in the husbandry AND biology of aquatic life.

2. Writing and using analogies that are easy to understand are wonderful. I wholeheartedly agree. But correction/discussion of dubious information should not be discouraged simply because we the readers are novices or the writer is experienced. If anything, it is even more important to exercise critical thinking and develop that habit at our novice stage.

Good luck.

 

[formsix]

Very interesting discussion.

So say someone has a tank with good (Sk8r sig) parameters and adds a few stony corals. If everything else remains the same, weekly water changes, etc., will Magnesium be the first thing to drop? And, if so, should that be tested weekly -- or more often -- and test Calcium only if Mg drops?

 

[acabgd]

If the calcium falls down below 420, eventually snail shells start dissolving and fish no longer get the calcium they need for bone and muscle.

Sk8r's post is great, but a newbie reading this and measuring his calcium at 380ppm would probably completely freak out.

 

[kurt_n]

... Sk8r knows the audience he writes these posts for, and nails it just about every time.

She.

If we want to be accurate and not spread misinformation.

 

[gbru316]

She.

If we want to be accurate and not spread misinformation.

:lolspin:


My apologies, Sk8r.

 

[kurt_n]

...If everything else remains the same, weekly water changes, etc., will Magnesium be the first thing to drop? And, if so, should that be tested weekly -- or more often -- and test Calcium only if Mg drops?

With my tank, cal/alk/mag seem to be depleted in equal amounts. They seem to rise and fall in equal proportions. Mag is normally 3x calcium levels.

 

[Sk8r]

Testing mg weekly is a good early warning. Testing all three every couple of weeks is not a bad idea. In the realities of daily life there will be the week you are snowed under at work or forget. If you constantly keep the mg in the 'safe' zone, the other two will not tend to give you surprises.

There is one other caveat: watch the expiration date on your tests. Particularly an expired alk test can lead to bad places, calcifications in the pipes and so on. So if you get a really weird or unexpected result from at test (a bennie to running them often and writing results in a log book is that you can TELL what is a weird result)---the first thing to check is the test itself, before you undertake massive remediation in your tank.

Learn to think of these three readings as a 'set', that if you have them in balance and keep them in balance, will keep you out of trouble, will generally keep your ph in good shape (barring something else odd) ---and will keep you in touch with what's going on in your tank.

In general, once you acquire a stony coral, you should acquire these 3 test kits AND the supplements along with it, to keep it in good shape, and not to have a low-calcium situation setting up in your tank. No, your fish will not melt, but the alk going down will NOT make them happy, because low alkalinity is not a good situation for fishy comfort and health, before it ever gets to their need for calcium---remember how those numbers are a set, and interlock. Fish are happy at about 7.9-8.3 alk as a range, so if your water parameters are going low in calcium, they're also going low in alk---remember: the three numbers are locked together.

My own procedure is to test mg to see how much wiggle room there is before it'll need more (a tank uses mg pretty slowly)---and if it's tending toward the bottom of the range, go ahead and raise it a smidge.

Now obviously calcium is not delivered by the tooth fairy, and you need a source that easily keeps the water 'saturated' with the right amount of calcium, so these hungry corals won't suck it all up and make a mess of your chemistry. The best thing to do is to put pickling lime or kalk into the freshwater topoff, and as long as you saturate (2 tsp per gallon, though you can start with one) the topoff water with kalk (calcium) and that mg holds, and while your buffer (alk) is set at 8.3, you're going to find your water holds steady in all 3 parameters as long as you can keep that going. If you have an ATO driving that, that's pretty well as automated as you can make it---, because kalk WILL NOT over-dissolve in that water. If you dump a lot of kalk in---ONLY 2 tsp max will dissolve (there's a trick with vinegar dosing to make it take more, but in general, the 2 is enough---and you can cut it to 1 if you have a new tank and only a few tiny corals.) If you have a tank larger than 70-100 gallons, packed with coral, that dose won't be enough, and you have to go to another trick to get the water to carry enough calcium, and that's a calcium reactor...but generally just spooning kalk into your topoff is enough. Anything that doesn't dissolve will dissolve when you add more fresh water, and don't generally bother with a kalk stirrer: what will ever dissolve dissolves fast with just one gentle swish, and that's that---lid the reservoir, because kalk forms a skin that's not desirable if exposed to air. You can use a strip of sponge to make a seal. And it's really THE most painless coral feeding operation you can do. Do remember it's applicable to stony coral: softies don't require that much, because they're not building stony skeleton.

If you constantly keep your mg up, and constantly supply calcium in the form of kalk (the cheapest source)---you will not have your alkalinity falling, with all those attendant problems. So while these jars of supplement are a bit pricey at the outset, if you do use kalk as your calcium supply (Mrs. Wages Pickling Lime is pure and cheap) you will manage to have growing corals and happy fish at the same time, without paying huge amounts for it.

 

[formsix]

Perfect!! Thank you so much! I just started to add LPS to my tank, tested those 3 parameters, and am currently right where I need to be. It's nice to know what I should be looking for in my testing, and roughly how often to test each thing (because a weekly battery seems like overkill, but aiming for weekly testing of a few things with a full battery every few weeks seems more reasonable).

Right now we have a (pretty dumb) manual top-off system going on -- we dump a pitcher of RODI water, maybe 1/3 gallon, into the tank roughly twice a day. We keep the water in a sealed 5g bucket next to the tank, so I can definitely add kalk to that. There shouldn't be any problem in putting that much in the tank at a time, right? An ATO is high on my list of wants, we just need to find the time to figure out what to buy and set it up. Thanks again for all the great information!

 

[Sk8r]

It would be easy to put a very simple ATO like an Avast one into that system, if you can protect the sensing tubes from being knocked askew. Small pump in the reservoir and some tubing leading up to the tank...securely fastened to prevent the thing coming loose and delivering kalk to your floor!!!! AND do NOT let the tube touch the water , ever, or it will siphon back and forth forever---a performance I once set up, and caught in time. [A siphon break like a little hole in the tube at its highest point can assure the tube clears when the pump is off, but I use 1/4" locline for my feed and it's a bit tiny for a siphon break.] Anyway, yes, you can do it. I'd start with light kalk at first (one tsp per gallon instead of 2, which is the full dose) so that if you're topping off infrequently you don't hit the tank with a whole lot of kalk at once (it has a ph of 12, though that falls fast.) Likewise try to put the topoff in without pouring it onto a coral, etc. Outside of that, it's pretty safe, even if one day when learning to use an ATO you accidentally white-out your tank. Looks awful, but I've never known it to harm anything.

Starting a log book of tests is a good thing, too, so that you can reference what it did when and how it behaves. I've set up a lot of tanks in moving about, and they all have their quirks.