ppm calcium carbonate

[Anonymous]

does anyone knows the ratio of
ppm of Caco3 in a tank to how many tsp that turns to.

example:

a tank reads 500ppm of Caco3
so wat is the anser to .how many spoons ofCaco3 would that mean in the tank??

 

[Anonymous]

Not as easy as that considering the vague nature of a teaspoon. With something more specific it is rather easy, ppm = mg/l plus allow for the fact the concentration if typically quoated for the calcium only, it does not include the carbonate part which is only present in rather low levels at the pH of a marine aquarium.

------------------
reefs.org
OZ REEF Marine Park
Don't worry, you will know when I am speaking as a reefs.org representative rather than a fellow hobbyist

 

[Anonymous]

I agree with DBW that it is complicated. I can give you an estimate, but I'm wondering at the reason for the question. Unless you are using a calcium reactor, you won't be dosing CaCO3 to a tank. Further, as DBW said, calcium in a tank isn't present as CaCO3, despite the fact that some kits may read this way.

Consequently, it is a bit unusual to want to know the number of teaspoons of calcium carbonate equivalent in a tank.

More often, people want to know how much a given amount of calcium chloride or other additive will raise calcium levels in a tank. Is that the root of the question?

------------------
Randy Holmes-Farley

 

[Anonymous]

my experiment is to find out how good some test kits are.
wat i came up with :

dissolve 1tsp of calcium carbonate in 1l of fresh water (originally reads 0ppm CA)
TEST IT THE RESULTS MATCHES 400ppm calcium.

 

[Anonymous]

Eli:

Are you really sure that you are testing and using calcium carbonate? Did it dissolve fully? If it is really calcium carbonate, almost none of what you added should have dissolved, giving a calcium reading of only a few ppm.

What matches what?

FWIW, the test you ran isn't suitable for evaluating Ca++ test kits. Calcium carbonate is poorly soluble in fresh water, and is kinetically slow to get to that solubility. Also, without a balance, you really don't know how much you added, even if it did fully dissolve. Thus, you won't know what the value really is.

Calcium chloride is more suitable, but you'll need a balance, not a measuring spoon to be within a factor of 2.



------------------
Randy Holmes-Farley

 

[Anonymous]

i should have said disolved in hydrocloric acid place it in 1l container and test (100mg of Caco3 will raise the 1l water to 400ppm Ca++)test the daily need of your reef then add it after several testing.

calcium chloride will leave unwanted chloride ions.

 

[Anonymous]

It does make it harder to understand what you are doing without a complete description.

For starters, 100 mg of CaCO3 dissolved in 1 L of anything will give 40 mg of calcium dissolved in that anything, or 40 mg/L = 40 ppm, not 400 ppm.

How could you measure 100 mg of calcium carbonate with a teaspoon?

This process leaves just as many unwanted chloride ions (from the HCl) as does calcium chloride.

I'd have to say I think from your several posts that you are getting bad information somewhere. Perhaps you should stop reading those Thiel web pages and just ask here (or elsewhere) about what you specifically want to accomplish.

------------------
Randy Holmes-Farley

 

[Anonymous]

Randy, I was thinking something similar

To get over the accuracy problems, they could go to large volumes and weights, so that the errors start to become insignificant or less significant.

eli,

Oh yeah, another variable you have to consider is the density of the calcium carbonate source you are using. This will vary significantly with grain size and the type you are using. If you are using coral sand, then you can get an estimate by filling up say a 1 litre container with it, and then measuring the weight.

If you really want to test the accuracy of a calcium test kit, then using a unit such as a teaspoon is a terrible way to go about it. You need to use something that is far more accurate, otherwise you are simply adding too greater errors into the whole equation as Randy pointed out.

As I said above, the larger the weights you use, then the more accurate things will be. What do you have at your disposal to weigh things with? Then you can work out the sort of mass that you will need to get an answer that is half reasonable.