Raising Calcium and Alkalinity Safely

[ellebelle]

On Saturday I finally got some Salifert test kits and tested my Calcium and Alkalinity in a reliable manner. Both my Calcium and Alkalinity were extremely low. So, I took out my bottles of 2-part and began by dosing 7.5mL into my tank. Next night, my levels were a little higher, so I dosed the same thing, then the next night they reached Ca 380ppm and dKh 7. I know this is on the low end of the target area. I'd be happier if they were a little higher, so I kept dosing the 7.5mL into my tank. My Ca and dKh are not moving. Therefore, I figure I have to up my dosage of 2 Part.

I don't have a doser, so I've been using the poor man's "pour" method and putting the two part into my sump. I'm afraid of raising the dosage too much because I don't want to shock my system. How much do you think I can dose at one time to see results? Or, how far apart should I space seveal smaller doses?

(I have a 29g tank with maybe 5 or so more gallons in sump and fuge. )

 

[Craig]

have you tested your Mg?

 

[loismustdie]

http://home.comcast.net/~jdieck1/chemcalc.html
I don't think it's the best, but you can use it as a guide.
Your Mg does come into play, so you want to test that too.

 

[bad coffee]

Start using kalk as your top off water.

B

 

[ellebelle]

No, I haven't tested for Magnesium. Anyone in the area have an Mg test kit I could borrow for a day until I can get my own?

But, it's my understanding that the presence of magnesium would PREVENT the precipitation of Calcium Carbonate, leading to high Ca and dKh readings. So, are you suggesting that my magnesium might be low, so it's precipitating out faster?

I use Instant Ocean Sea Salt and did 10% water change on Sunday.

Brett, as soon as I get my ATO set up, I will be topping off with Kalkwasser.

 

[loismustdie]

Brett, as soon as I get my ATO set up, I will be topping off with Kalkwasser.

Lissa, you have a pretty good bioload in a 29. I think kalk would not be a good move for you if you plan to continue using 2 part if you run a PO4 reactor. Your PO4 reactor will suck down a lot of the alk and not be effective for very long at pulling in PO4. Just my 2 cents on that one. If you will no longer do 2 part when you start the kalk or don't use PO4 reactors, disregard.
All I can say about Mg is that if it is out of wack, it can lead to false reading of Ca and alk.
I feel that necessary things to be tested after cycle are Ca, alk, Mg, NO3, PO4 and if you have a pH meter, good. There are others. Some will disagree with me. But these are what I like to keep a closer eye on and it has been working for me.

 

[ellebelle]

I was planning to stop dosing 2-part when I start dosing Kalk. Mg is the only test kit I don't have at this point.

 

[PalmTree]

Its funny because I had the same problem a few years ago. My calcium dropped despite my religious 2 part routine. I upped the dosage but it would not go beyond 390 or something like that. I tested my Mg and it was well below what it should be. After a water change and the addition of ESV Mg additive my Ca and Alk shot right up. I don't even know what in my would consume Mg. I've never had to add it since.

 

[loismustdie]

I was planning to stop dosing 2-part when I start dosing Kalk. Mg is the only test kit I don't have at this point.

That's cool.
I went through all of this during the summer. Same as Palmtree. My Ca was close to 600 and my alk was around 6dKh. My Mg was way low. I did 2 very large water changes and I used the calculator I posted above (I only did half to 2/3 the dosages the calculator said) and I got it stable. Keep in mind that I had gotten my PO4 under control before I even bothered with the Ca, Mg and alk. At one point, my PO4 was so high that there was not a shade of blue dark enough on a Salifert kit for me to read it.

 

[Deanos]

I don't even know what in my would consume Mg. I've never had to add it since.

Magnesium in Reef Aquaria

Excerpt: In terms of the amount of magnesium consumed, the primary use in reef aquaria is in calcification. When calcium carbonate skeletons are deposited, magnesium often gets into the skeleton in place of calcium. It is not entirely clear whether this is something that organisms “try” to control or not. Nevertheless, the amount of magnesium entering the skeletons of different organisms varies greatly.

Now you know, and knowing....

Dean

p.s. Magnesium is the third most abundant ion in seawater, behind sodium and chloride. It is also intimately involved in a great many biological processes in every living organism. Nevertheless, the only time that it comes to the attention of most reef aquarists is when it is suspected of causing a problem in maintaining appropriate calcium and alkalinity.