Balancing alk, Ca, Mg and pH

[calvinci]

hi, I am dosing kalk from a still reservoir, only mix kalk once a month and let it drip for the whole month. So far my parameter as below :

pH 8.1 in the morning 8.3 just before lights off
alk 2.85 (dKH 8)
Ca 360ppm
Mg 1240ppm

All seems ok except Ca should be 400ppm to match the alk, so should I dose seachem advantage Ca to bring up the Ca? Can I dose 2 teaspoon a day on top of the kalk dripping, so at the fifth day, it will be 400ppm? If not, what's the best way to dose it?

[mhurley]

Yea, you need to get that Ca up. The downside to kalk is that your additions are limited to your evaporation rate. So you can try and speed up evaporation with a fan over your sump or you will have to look into other methods to supplement your calcium, like Turbo Ca or some calcium chloride supplement (sorry, never use Seachem Advantage so I wont comment on it).

[mhurley]

Also...Required reading for the calcium/alkalinity challenged :D

Solving Calcium and Alkalinity Problems
http://www.advancedaquarist.com/issues/nov2002/chem.htm

How to Select a Calcium and Alkalinity Supplementation Scheme
http://www.advancedaquarist.com/issues/feb2003/chem.htm

[Stevan]

IIRC you can add Vinegar to your Kalk to raise the Ca...Ddo a search for how and how much.

[mhurley]

No. You add vinegar to kalk to lower it's pH. It has no impact on Calcium.

[Mariner]

I drip about 3/4 gallon of Kalkwassser each night in my 75 gallon tank, and I still have to add 1+ teaspoon of Reef Advantage every night to maintain calcium in the 400-420 range (I have several SPS and a clam, so my tank uses a good bit of calcium). I also have to add that much buffer or more to maintain alk at 8-9 dKH
Long story short, if your tank uses much calcium at all, just dripping Kalk is not likely to keep up with demand in the long run. Boosting with a calcium additive like Reef Advantage, and Buffer (like Reefbuilder or Kent's Superbuffer or Homemade) will also be necessary.
At the present, raising your calcium over several days according to the directions on ReefAdvantage (or whatever you're using) would be the thing to do.
HTH,
Mariner

[DrBDC]

It does increase the calcium dose by allowing more lime to be disolved. If your Ca and alk aren't at levels, though the kalk is to maintain once you have it where you want it. It really shouldn't be looked at like a way of increasing either ca or dKh. I use Randy's 2 part as needed for ca and alk to adjust those while doing all kalk topoff at full saturation w/o vinegar.

[mhurley]

IMO, when calcium demands using Kalk can't be sustained any longer, it's time to looking into a calcium reactor. Yes..they are initally expensive, but cheaper long term and very hands off.

[DrBDC]

If you use the two part as well, you can go to very high levels. But that is a daily chore. I haven't done the ca or kalk reactors but from what I understand, they're hands off til the media expires. How long that is I have no idea though.

[calvinci]

thanks, I will add CaCl, by the way, drip kalk alone can't keep up with the Ca demand, without adding Ca supplement?

I thought Randy's article say this is better than Ca reactor, as it will not introduce additional pH or Cu or other impurities to the tank. And kalk is self purifying.

[bertoni]

I like limewater for the reasons you state. If your kalk drip can't keep up, likely it's because the tank doesn't evaporate enough water per day. You can modify the evaporation rate with a fan in most cases.

In other cases, there might not be enough aeration to keep the pH down, I suppose, which can also be helped.

[calvinci]

so far the pH is ok, I will add fan and vinegar if needed. BTW is there a possibility of snow storm even thou my tank alk and Ca is not saturated yet?

[bertoni]

I wouldn't expect one if your parameters stay close to the ones you report.