Help! My calcium level is suddenly low!

[jmauney]

So my calcium and Alk levles have been fine 400s calcium and 10 ish alk. Well we went on vacation for a week and a half and now my Calcium is showing 260 and my Alk at 9!!!! I think the alk is acceptable but the Calcium is horrible! Brs calculator is saying add 1637 ml of liquid calcium carbonate??!!! I cant imagine that that would even be safe. Please help!! My setup is aprox 100 gallon total system volume (90 gallon display, 30 gallon sump, minus rock and sand) i have a couple larger colonies of sps and a few lps and some softies, nothing major. Please advise on my best course of action! I had order kalkwausser?? to add into my ATO to keep my cal and alk where they need to be but from what i understand my system needs to be where i want the levels before i start the kalk.... oh yes im measuring my alk and cal with Hannah testers. Thanks for any help!!

 

[Shirak]

I would double check with an alternative method if possible, and have you checked anything else like Salinity?

 

[jmauney]

I would double check with an alternative method if possible, and have you checked anything else like Salinity?

Yes salinity is spot on 1.025... I've actually brought it up from like 200 when we first got back home... I May have to go find a calcium test kit.....

 

[Rybren]

I'd recheck with a different calcium test kit. Without something really strange going on (and I can't think of anything), calcium won't drop that fast.

 

[melanotaenia]

You have left a lot of information out; do you dose your aquarium daily or do you rely on water changes to replenish your levels? A drop like this is unlikely, and most likely a testing error, but it would be good to verify and monitor.

If you are using a Hannah tester I would not trust the Ca+ reading until you can verify with a second, more reliable test such as Salifert or RedSea. If in fact your Ca+ level is not that low and you dose according to the level you read now, you could end up causing more harm to your corals.

Also, take a look at your coral and see how they look; if they look ok then I would not add a drastic amount of Ca+ until you can verify the levels.

 

[Lovefish77]

Also keep an eye on alk as you raise calcium. The more calcium you dump the more alk will go down, I read that they move in opposite directions.

 

[jmauney]

I have

You have left a lot of information out; do you dose your aquarium daily or do you rely on water changes to replenish your levels? A drop like this is unlikely, and most likely a testing error, but it would be good to verify and monitor.

If you are using a Hannah tester I would not trust the Ca+ reading until you can verify with a second, more reliable test such as Salifert or RedSea. If in fact your Ca+ level is not that low and you dose according to the level you read now, you could end up causing more harm to your corals.

Also, take a look at your coral and see how they look; if they look ok then I would not add a drastic amount of Ca+ until you can verify the levels.

I have only been dosing seachem reef fusion every other day because that's all it's really needed to keep it in the correct levels... Also I thought the Hannah checkers were the better tests??? Maybe I need to research a little better!!

 

[robbyg]

I have

I have only been dosing seachem reef fusion every other day because that's all it's really needed to keep it in the correct levels... Also I thought the Hannah checkers were the better tests??? Maybe I need to research a little better!!

Hanna calcium checkers work fine. I can read a freshly opened Ca Standard solutionto within 1ppm.
You do need to know how to use it right. There is very good video on the subject.

 

[jmauney]

Hanna calcium checkers work fine. I can read a freshly opened Ca Standard solutionto within 1ppm.
You do need to know how to use it right. There is very good video on the subject.

Yes I've been using it for a year

 

[Randy Holmes-Farley]

Calcium cannot drop without a corresponding alk drop (or addition). To drop calcium by 100 ppm would require a drop of nearly 15 dKH. So test error is the likely explanation.

As an aside, Seachem Reef Fusion is not properly designed for 1:1 dosing, so do not use it assuming it is.

 

[jmauney]

I have been using it per directions with fine results until recently?? Could my Reagent possibly have gone bad?? Also it's marketed as such so I def won't be using it anymore!!

 

[Randy Holmes-Farley]

I have been using it per directions with fine results until recently?? Could my Reagent possibly have gone bad?? Also it's marketed as such so I def won't be using it anymore!!

You can use it ok, it just is not balanced 1:1 despite the claim.

I show the imbalance of it here:

Seachem Reef Fusion is not properly alk/calcium balanced for 1:1 dosing

A recent thread in the chemistry forum from someone who found that calcium increased with this product while maintaining alkalinity and using 1:1 dosing as advised by Seachem provoked me to check it's manufacturer specifications to see if it was a balanced additive. From Seachem's claims about...

www.reef2reef.com

From Seachem's claims about it, it is easy to see that it is not properly balanced, despite claims from Seachem that it is. For those who do not care to read further, it seems to have 15-25% too much calcium based on their specifications.

http://www.seachem.com/reef-fusion.php

from it:


"Most concentrated two part system; simple 1:1 ratio"

"Reef Fusion 1™ provides not only 100,000 mg/L of ionic calcium, but also includes biologically appropriate levels of magnesium, strontium, boron, iron, manganese, and molybdenum."

"Reef Fusion 2™ contains a mixture of carbonates and bicarbonates at an alkalinity of 4400 meq/L. "

Let's explore that.

Calcium is 100,000 mg/L. Calcium weighs 40 g/mole, so that is 2.50 moles/L.

The alkalinity is 4.4 equivalents/L.

To make calcium carbonate, each mole of calcium reacts with 2 moles of alkalinity. So 2.5 moles/L of calcium reacts with 5 moles/L (5 equivalents per L) of alkalinity.

In terms of making pure calcium carbonate, this product has excess calcium. Specifically, it has 13.6% too much calcium.

It is actually a bit tricky to know exactly how much calcium and alkalinity to have in a two part for two reasons (detailed below), but it is expected that the demand for calcium in a reef tank when using a two part is below the ratio needed for production of pure calcium carbonate due to replacement of some of the calcium demand by magnesium and strontium getting into the calcium carbonate crystal in place of calcium.

In my DIY two part (like from BRS), I chose to use slightly less calcium relative to alkalinity. My calcium part is intended to have 37,000 mg/L calcium (0.92 M) and the alk part has 1.9 eq/L alkalinity. Thus it is intended to have a slight excess of alkalinity relative to calcium. It may not be perfect, depending how the factors discussed below play out in any given reef tank, but it is in the right direction.

 

[jmauney]

Thanks so much for the heads up

 

[GillMeister]

I'll ask this question, because there are no stupid questions. Right? Is it possible to cause a calcium crash by dosing too much? Can it precipitate if too concentrated or is it simply not possible to do this in a reef tank? Again, I'm just some guy, not a chemist.

 

[jmauney]

So as of today the calcium has come back up to 385 and alk is up to 10.1 dkh!!!!!... Also magnesium is 1450. That's with 4 straight days of dosing 20 ml each of fusion part 1 and 2

 

[Randy Holmes-Farley]

I'll ask this question, because there are no stupid questions. Right? Is it possible to cause a calcium crash by dosing too much? Can it precipitate if too concentrated or is it simply not possible to do this in a reef tank? Again, I'm just some guy, not a chemist.

Yes, but it has to be very, very high. Doubling calcium (say, from from 420 ppm to 840 ppm) will have the same tendency to precipitate calcium carbonate as alk doubling (say, rising from 7 to 14 dKH), or pH rising by 0.3 pH units. As you can see, the latter two are more likely in a reef tank that calcium doubling.

 

[jmauney]

Ok so little update, had been dosing my Reef fusion 1 and 2 the last 4 days straight at the 20 ml suggested dose and last night my readings are 385 calcium, 10.5 alk and 1450 magnesium.... I did check my freshly made saltwater this am and it's only reading at 350 so maybe I got a bad batch of salt, it's 350 at SPG of 1.025 and it should be at least 400+ with that SPG according to the side of the bucket, using Reef Crystals btw. Changing my salt to Fritz RPM .

 

[Shirak]

I did check my freshly made saltwater this am and it's only reading at 350 so maybe I got a bad batch of salt, it's 350 at SPG of 1.025 and it should be at least 400+ with that SPG according to the side of the bucket, using Reef Crystals btw. Changing my salt to Fritz RPM .

What are you using to measure SG?

 

[jmauney]

What are you using to measure SG?

Refractometer

 

[Shirak]

Refractometer

That's good but have you calibrated it or verified it's reading accurately? Could be off. Possible the salt mix is the issue but they are usually pretty close to the advertised specs.