HELP Very low Calcium

Dayson · Dec 8, 2015

Running a 180g mixed reef tank and came home today to things not looking so hot. Things have not been looking as good for the last few weeks so I have been doing more water changes than usual, just did a 15% on Sunday. Checked my params and found the calcium to be 175 ppm! I am not dosing anything so that could not be out of wack. Other params are:

Salinty - 1.026
Ammonia - 0
Nitrite - 0
Nitrate - 10
Phosphate - 0.04
Alk - 8

I tested the calcium of freshly mixed RODI water using reef crystals and found it to be about 175ppm also. Im thinking i got a bad batch of salt. I have Reef Fusion 1 on hand but have never used it as I have always depended on weekly water changes to keep params stable.

Should I use Reef Fusion 1 to bump of Calcium? (I also have reef fusion 2 on hand) If so, how much? Should i slowly bring it up or jump it straight back up to the 420 range? I have a new box of salt arriving tomorrow and plan to do a large water change ASAP.

I have also confirmed to test kit is accurate by testing the water in the brothers tank (410ppm) and straight RODI water (0ppm)

Please help as my SPS is looking pretty bad.

JimWelsh · Dec 8, 2015

I'm not sure what Randy would say, but if it were me, I'd get the Ca up to at least 350 PPM as quickly as possible. But, if it were me, I'd be using relatively pure calcium chloride, and not the mixture that Reef Fusion is. Still, the amount of Mg, etc., that Reef Fusion is adding is likely not to excess, and especially not if you are planning a reasonably large water change soon anyway. I'd say use the ReefFusion 1 to get alk to at least 350, pending any response from Randy.

Downbeach · Dec 9, 2015

Have you checked your Ca with another test kit? It would be prudent to get another opinion before making any major changes. Have you calibrated/checked the accuracy of your SG measuring device? If its off you may not be adding enough salt mix when you make up your WC water, and by extension not enough Ca, Mg and Alk. When you open the new box of salt mix, make sure you thoroughly mix it to ensure that there hasn't been any elemental stratification that may have occurred during shipping. If you find that your SG is indeed low, make the correction(s) to your make up water, and use freshly made SW in your top off to get your DT back to 1.026, and then return to using plain RO/DI water. Then revisit the test(s). If you have to, you can bring your Ca up at a rate of up to 50ppm per day. The Seachem product will work fine, but as Jim said plain Calcium Chloride will do the same thing, and more economicaly.

reefwiser · Dec 9, 2015

Dayson said:
I am not dosing anything so that could not be out of wack.
Please help as my SPS is looking pretty bad.

Not dosing 2 part or 3 part with SPS will not go good. They require the proper Calcium and Alk constantly. An as they grow the amount they up take increases.

Randy Holmes-Farley · Dec 9, 2015

I'm skeptical that the calcium is really that low. It would have to be from a bad batch, and that is pretty uncommon with RC. Not impossible, but testing error is far more common. Check the new salt mix and compare to the old one side buy side before doing anything big with the tank. Make up more water than a small fraction of a bag or bucket which might be off from settling/inhomogeneity.

Water changes are not generally the best way to deal with such an issue, but if the batch of RC really is off, then you can't know what else might be off besides calcium and water changes might be useful.

If it is really that low, I agree that I'd raise it fairly rapidly, and I'd use calcium chloride to do it. it will take a lot, and since you may not have enough of the two aprt around, I'd buy some calcium chloride. Then I'd raise it by 50 ppm per day for several days.

Dayson · Dec 9, 2015

I am very skeptical as well. However, I tested the DT water multiple times with the same result using the same method I have always used. I am using the red sea reef foundation pro titration test kit. As i mentioned, to make sure that the test kit had not gone bad I went to my brothers and tested his tank. His tank showed a Calcium of 415. I have a liter bottle of Reef fusion on hand so I added a cap full to the tank. The problem is I do not know how much that will increase my levels. The directions said that a tank my size should be dosed about 3.5 cap fulls every two days so I am guessing one cap full should not raise it significantly. Do you know how much it will take to raise a ~225g system 50ppm per day? I can buy some calcium chloride at the LFS today and start using that.

I will be interested to see how the new box of reef crystals tests.

As far as dosing, I know I need to start and the wife has bought a pair of dosing pumps and chemicals for Christmas. Hopefully I can make due until after the holiday.

Thank you for all the responses. I will update when possible.

Randy Holmes-Farley · Dec 9, 2015

It takes more than you dosed. To boost calcium by 50 ppm with it will take 0.43 gallons added to 225 gallons of water.

Dayson · Dec 9, 2015

Thanks again for the reply...I was way more scared to overdose than anything else...

Downbeach · Dec 9, 2015

Use this calculator, fill in the blanks for your system and select the appropriate supplement from the drop down menu to get your dose.

saltyhog · Dec 9, 2015

Double check your salinity as someone mentioned above!

iman7045 · Oct 12, 2021

Randy Holmes-Farley said:
It takes more than you dosed. To boost calcium by 50 ppm with it will take 0.43 gallons added to 225 gallons of water.

Hi there, How would one go from meq/L to mL for balancing out alk to calcium?

Randy Holmes-Farley · Oct 13, 2021

iman7045 said:
Hi there, How would one go from meq/L to mL for balancing out alk to calcium?

Depends on what exactly you are dosing, and the aquarium volume.

This calculator helps in many cases:

http://reef.diesyst.com/chemcalc/chem_calc3.html

iman7045 · Oct 13, 2021

Randy Holmes-Farley said:
Depends on what exactly you are dosing, and the aquarium volume.

This calculator helps in many cases:

http://reef.diesyst.com/chemcalc/chem_calc3.html

Ok yeah thats the calculator i use just didn’t understand the meq/l part to dose

iman7045 · Oct 13, 2021

iman7045 said:
Ok yeah thats the calculator i use just didn’t understand the meq/l part to dose

Would that be 3.45ml of part A of esv?

ChaosAquaculture · Oct 13, 2021

I doubt the cal is actually that low, I’d try using a different test kit as well. Salifert snd Red Sea are my favorites. Also, what’s your mag? If your alk and cal are really that far off there’s a mag problem as well - kali

Randy Holmes-Farley · Oct 13, 2021

meq/L is the same type of unit of measure as dKH.

The calculator cannot (should not) tell you what your target is, it just tells you how to attain it.

Randy Holmes-Farley · Oct 13, 2021

ChaosAquaculture said:
I doubt the cal is actually that low, I’d try using a different test kit as well. Salifert snd Red Sea are my favorites. Also, what’s your mag? If your alk and cal are really that far off there’s a mag problem as well - kali

The post you are responding to is 6 years old. He probably solved it by now.

iman7045 · Oct 13, 2021

Randy Holmes-Farley said:
meq/L is the same type of unit of measure as dKH.

The calculator cannot (should not) tell you what your target is, it just tells you how to attain it.

Ah ok yeah gotcha the meq was throwing me off a bit to figure out the alk i needed to dose thanks for clarifying it!

Randy Holmes-Farley · Oct 13, 2021

iman7045 said:
Ah ok yeah gotcha the meq was throwing me off a bit to figure out the alk i needed to dose thanks for clarifying it!

meq/L is a scientist unit of measure of alkalinity, and dKH is mostly a hobbyist unit.

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com

meq/L

A milliequivalent per liter (meq/L) is a unit of the concentration of a substance or collection of substances. It is equal to one milliequivalent dissolved in 1 L of fluid, or 0.001 equivalents dissolved in 1 L (eq/L). Aquarists most often encounter it when measuring alkalinity, which is a little unusual in that alkalinity is not a measure of a single substance in solution, but rather the aggregate of several reactive species.Alkalinity is a measure of the amount of acid necessary to reduce the pH of water to the point where all carbonate and bicarbonate have been converted into carbonic acid (about pH 4.2 in seawater).In seawater, nearly all of the alkalinity is provided by bicarbonate and carbonate, although some is contributed by other ions such as borate. Consequently, alkalinity can be used by reef aquarists as a surrogate measure for bicarbonate and carbonate which are taken up by calcifying organisms. The units of alkalinity can be meq/L (milliequivalents per liter), dKH (degrees of carbonate hardness) or ppm (meaning ppm of calcium carbonate equivalents).1 meq/L = 2.8 dKH = 50 ppm CaCO3 equivalents.Seawater has an alkalinity of about 2.5 meq/L = 7 dKH = 125 ppm CaCO3 equivalents.An article explaining in detail what alkalinity is and what its units mean is online here. A calculator for converting between different alkalinity units is online here.A calculator for determining how much of different supplements to add to boost alkalinity, as well as calcium and magnesium, is online here.