Calium

[stevetopthat]

I have not added calcium for 3 weeks to get the level down from 1000 ppm to 400ppm and I'm still at 720ppm. Any ideas on why the level is still so high?

 

[Brenden]

What is the PH and Alk? Never thought you could get it that high without fallout.

 

[steve-s]

It's a miss reading. Retest, test your saltmix and do a few water changes. The problem is most likely magnesium related. Have that tested as well.

 

[stevetopthat]

Calcium

The test on Alkalinty was dKH is 12.0 and salinity is 1.026. I tested the water I buy at the store Natural Sea Water and it was 400ppm. Im planning a 50% water change this weekend. Thanks for your help.

 

[LakeEd]

Steve,

I've never heard of someone with quite that high of calcium level! Please keep us posted as to how things are doing, especially with your water changes ahead of you.

As Steve-S mentioned... you may wish to test your Mg... because it interacts with the Calcium in our tanks... and having those numbers may give you another clue why your tank is where it is today.

 

[IAP Brian]

I would take another look at alk as well. Try another brand of test kit or have another LFS check it for you. Every water sample I have seen that had extreme calcium level also had alk readings in the basement. I don't know about magnesium affecting ca readings but that may contribute. Also try posting this in the chemistry forum and get Boomer's advise.

*** thanks Nikki for moving to chemistry forum***

 

[NaH2O]

*moved to Chemistry Forum*

What brand of test kit are you using? Keep up with the water changes. What were you using to dose calcium?

 

[Scooterman]

I'm up for the ride but I do agree something is admist here, 1,000 sounds like something wasn't right when testing. These things happen

 

[james734]

My only advice is make sure your doing the test correctly. I made a mistake one time by only putting in a 1ML of water in when the test called for 2ML. I was scratching my head try to figure out why my calc was low. So add some dry calc powder retested same results. It took water to the LFS for testing, it tested fine. It wasn't until I sat down and tested with the directions open and reading them that I caught my mistake. DUH.... Anyway 1000 sound like a testing error or something is way out of wack here.

 

[morgan]

i had 600 and that was band a thoushand would suck water changes are ur best way out of it maybe to much lime water
it dose take awhile to drop took me about a month to drop a 100also your calk reading should be low because a high calcium saturation inhibits calk to rise
best of luck with the problem

 

[Boomer]

What did you add to get it that high calcium chloride. You could get the Ca++ that high with calcium chloride. What will dictate the water going into a snow storm will be the pH and Alk with Ca++ at 1,000 ppm.


Where non-biological precipitation is more common( from Randy)

#1...............................#2
pH = 8.2........................pH = 8.2
Calcium = 410 ppm .........Calcium = 820 ppm
Alkalinity = 5.0 meq/L......Alkalinity = 2.5 meq/L

#3................................#4
pH = 8.0.........................pH = 8.7
Calcium = 410 ppm ...........Calcium = 410 ppm
Alkalinity = 8.0 meq/L.......Alkalinity = 2.5 meq/L

#5
pH = 8.45
Calcium = 410 ppm
Alkalinity = 4.2 meq/

Look at the third one, where the pH is 8.0 and the Alk 8.0. If we cut that Alk in half to 4.0 the Ca++ would go up by 2 x based on #1 & #2 and around another .5 x if we lowered pH the from 8.2 to 8.0 or 410 x 2.5= 1025 ppm Ca++, with alk at 4 and pH 8.0.

So, it would be nice to know what the pH is

So with all this said, it is possible but I think there may be a testing error, similar to what Jim has state and others have mentioned.

As far as Mg++ test goes it is often assumed that low Ca++ or not being able to get Ca++ up, is due to low Mg ++. So Mg++ levels will have no bearing, if Ca++ is that high.

Some papers that Randy and I have looked at seem to suggest that Mg++ levels have no bearing on Ca++ levels, although another one says just the opposite

 

[steve-s]

As far as Mg++ test goes it is often assumed that low Ca++ or not being able to get Ca++ up, is due to low Mg ++. So Mg++ levels will have no bearing, if Ca++ is that high.

Some papers that Randy and I have looked at seem to suggest that Mg++ levels have no bearing on Ca++ levels, although another one says just the opposite

Not sure if I would completely agree with that last sentence. Your going to have to help me with this one.

I have on several occasions myself found Mg++ to have a very direct impact of Ca++. I have also found that it has little to do with low Ca but rather high or what might appear to be a climbing Ca++.

I don't know how you would represent it chemically but I have personally experienced a low unmaintainable alkalinity and a high climbing Ca. Magnesium was at a very low 700-800 ppm (can't remember exactly). Through daily additions of Mg++ (not water changes), the depressed alkalinity and wild Ca respectively became steadier and sustainable. Before adding the MgCl, buffer additions would fall dramatically in less than 12 hrs, 3.0 mEq/l down to 1.75 mEq/l (or lower). When Mg++ is in the right range, the alk would only drop at a normal rate daily 3.0 mEq/l down to 2.85-2.87 mEq/l.

How does that happen if Mg++ does not play a significant role?

 

[MikeS]

My understanding of that whole Ca/Mg/Alk mess is that Mg helps keep Ca from precipitating out of suspention into calcium carbonate, but it's not really a balance issue between Ca and MG like it is between Ca and carbonate/bicarbonate levels. And to me, anyway, that would explain why you (Steve) were able to maintain better Ca/Alk levels with the proper Mg level, because it (Ca) was no longer precipitating out of suspention. I could be off here, I'm no chemist...

MikeS

 

[steve-s]

because it (Ca) was no longer precipitating out of suspention.

See that's the part of the problem I am trying to wrap my brain around. If Ca where precipitating due to low Mg, why would the test kit keep registering a much higher Ca value than would be considered possible before it did actually fall out of solution. If the test kit registers properly when Mg and alk are normal, the test kit is not faulty, just inaccurately reading the results.

The only answer I keep coming back with is the test kit itself is not able to properly report the value because there's not enough "information" available to make a complete picture. So in order for Ca++ to be read accurately by the kit, the associated ions with alkalinity and Mg need to be at least near a reasonable range first. Get my meaning?

 

[Boomer]

As Mike has stated it has been seen quite often, that if the Mg++ is low it is hard to keep up the Ca++. The theory is as Mike has stated, normal Mg++ stops Ca++ from leaving solution.

I have on several occasions myself found Mg++ to have a very direct impact of Ca++.

Many reefers have claimed that and it may very well be. Meaning, Low Mg++ will/may give problems trying to keep up the Ca++. Almost every time some bring ups "I can not keep my Ca++ up " the answer is "what is your Mg++ it may be low"

I have also found that it has little to do with low Ca but rather high or what might appear to be a climbing Ca++.

This is the first I have heard of anyone who has claimed that their Ca++ goes up easily with low Mg++ . What you are claiming is the opposite of all I have seen on boards.

On another note, increased Cl- will make things go more easily into solution. So, it may have been the chloride. Yet another issue, is fresh carbonate substrates will often pull Mg++ out of solution producing Hi Mg-Calcite, lowering Ca++, pH and Alk.

You mean this last sentence ?
Some papers that Randy and I have looked at seem to suggest that Mg++ levels have no bearing on Ca++ levels, although another one says just the opposite

We are not sure if it is correct or not. We have to remember that we are often adding sulfates and chlorides with these additives. Sometime the obvious, Mg++ being the controller, may be misread.

I would be more than glad to show you the papers but on Tuesday my F drive seems to have crashed and I have no access to it. I have the pdf's of these articles in there. If I can not get this F drive to work I will loose 5 years of collected data for us guys

 

[Boomer]

So in order for Ca++ to be read accurately by the kit, the associated ions with alkalinity and Mg need to be at least near a reasonable range first.

I don't buy that at all, unless you are using a photometer or have some bad brand test kit. So, who's kit are you using ? I have never heard that before.

 

[steve-s]

So in order for Ca++ to be read accurately by the kit, the associated ions with alkalinity and Mg need to be at least near a reasonable range first.

I don't buy that at all, unless you are using a photometer or have some bad brand test kit. So, who's kit are you using ? I have never heard that before.

Not suggesting it was true, just offering up a possibility. Grasping at straws if you will...

I still don't understand how a test kit (Salifert) can read a high Ca level while Mg is low and the same kit reads a normal Ca after the Mg was corrected? The only addition being made is MgCl and MgSO4, no water changes.

 

[Boomer]

Steve

In short, most kits measure T-Hardness, as CaCO3 and the Mg is part of this expression. Meaning, the kit is seeing both as the same ion more or less. They then measure the Ca++ separately, which is then subtracted from the
TH = Mg++. TH - Ca++ = Mg ++

Because the way a photoemter works and ranges they give, the two can cause intrerference if one is to high.


But I will ask Habib for you bud

 

[Boomer]

Steve
Hi Boom,

The calcium value measurement is not sensitive for variations in magnsieum. Anything from say 100 - 2500 ppm Mg would be OK.

Looks like the addition of Mg helped him to prevent abiotic precipitation of CaCO3.

Cheers,

Habib

 

[steve-s]

Thanks Boomer, clear as mud though