Low Calcium Problem?

[Navyblue]

Hi Randy,

On 02/07/2004
Calcium: 380 ppm
Alkalinity: 9 dKH

After finding my calcium is a bit on the low side, I decided to drip some kalkwasser.

On 04/07/2004
Calcium: 400 ppm
Alkalinity: 11 dKH

I do not know whether it is a problem or not, I feel that the trend in increase in calcium level is lesser that what it is supposed to be. The increase in alkalinity is much higher than the increase in calcium when adding a balanced Ca/alk additive (kalkwasser).

Should I just add some calcium chloride or similar stuffs to tweak the calcium level a bit?

Or there is some other problem causing the calcium level to be suppressed? Low magnesium? I do not have a magnesium test kit and never dose any.

Or it is normal and I just have to continue dosing kalkwasser?

Thanks in advance. :)

[dragon_slayer]

...........Should I just add some calcium chloride or similar stuffs to tweak the calcium level a bit?

that would work best IMO with your current settings.


Or there is some other problem causing the calcium level to be suppressed?

your levels came up so there is nothing supressing them, they were just depleted by consumption from the tank. the normal consumption of Ca and Alk will deplete the Alk much faster then you'll notice the Ca but they are still ballanced none the less.

hth
kc

[Randy Holmes-Farley]

I agree with KC. :)

The increase in alkalinity is much higher than the increase in calcium when adding a balanced Ca/alk additive (kalkwasser).

Actually, it was darn near perfect. :)

Calcium went up by 20 ppm, and so alkalinity should have risen by 2.8 dKH. It went up by 2 dKH, which over two months and with testing uncertainty is perfect. :)

If you want to raise calcium a tad more, and not raise alkalinity, then a little calcium chloride will do that, yes. This calcualtor will show how much is needed:

Reef Chemicals Calculator
http://www.kademani.com/reefchem.htm

[Navyblue]

Sorry for not making myself American enough in my date expression, the date format I use is actually dd/mm/yyyy, so the testings are done within 2 days interval.

Thanks for your replies KC and Randy! Learned something today.

[Randy Holmes-Farley]

Oh OK. Still, the results are close enough.

Good luck. :)

[Navyblue]

I have another question here :)

Just a thought, if I use vinegar to neutralise kalkwasser and turn it to calcium ethanoate, can I use it in place of calcium chloride? Or it will not be neutralised totally? If it is possilbe, then I would not need to buy calcium chloride supplement as I don't think I will use it often.

Thanks. :)

Editted: Or it will not be economical actually as I'll need a lot of vinegar to do that?

[Randy Holmes-Farley]

Taking the lime all the way to calcium acetate is not optimal, IMO.

In general, using pure calcium acetate is an OK way to supplement calcium and alkalinity in a balanced fashion, and it is about the only single chemical that can be added that will supplement both well. Salifert has a product that contains calcium acetate.

The drawbacks to making calcium acetate from vinegar and lime are:

1. If you use a lot of it, the acetate uses up O2 as bacteria and other organisms use it, so the O2 levels may be lower than otherwise.

2. Any impurities in the lime will go into the aquarium as that much vinegar will lower the pH to the point twhere they are soluble. The usual amounts of vinegar (given below) do not make complete calcium acetate, so the pH is not so low, and the impurity concern is not so great.

3. That much vinegar may make the pH too low in many aquaria.

4. The acetate can drive the growth of unusual organisms, probably bacterial mats, that some folks have seen.

The usual recommendation if you just what more potency from limewater is 3 teaspoons lime per freshwater gallon, and 45 mL vinegar per freshwater gallon.

[Navyblue]

If vinegar is used along with kalkwasser as mentioned, will it tweak the calcium/carbonate balance significantly?

Thanks :)

[Randy Holmes-Farley]

No, it doesn't really change the "balance". It allows more limewater to enter the aquarium (if you add more soilid lime to the limewater) and a larger addition will be noticed first in an alkalinity increase.

Vinegar also keeps the tank pH from getting as high during the day.

[Navyblue]

Thanks :)

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)

[Navyblue]

Hi Randy and the rest :),

Sorry to tell you that the story has not ended.

After dripping more kalkwasser, I've just tested the the result is as follows:

Calcium: 360 ppm
Alkalinity: 12 dKH

Is there anything wrong here? The gap between calcium and alkalinity seems to be widening.

[Randy Holmes-Farley]

I wouldn't get too worried about day to day changes as much of the changes will be test kit noise.

Nevertheless, if you want to do something, I'd boost calcium with some calcium chloride, and keep using the limewater. :)