Testing a Kalkwasser source?

[Garf]

I’ve bought a load of Kalkwasser (well, calcium hydroxide). I’ve got an idea that there should be a simple way to check if it’s acceptable to dose to the tank intentionally, as opposed to unintentionally, lol.

Perhaps we could compare bulk supply results.

I imagine an ICP test would give an idea. Can anyone describe a reliable method of obtaining a solution to send away and test? I’m thinking a saturated solution should be ok to have tested? Perhaps dissolving some with Hydrochloric and making a solution from that to include the normally precipitated stuff?

Thanking you muchly.

 

[Randy Holmes-Farley]

I’ve bought a load of Kalkwasser (well, calcium hydroxide). I’ve got an idea that there should be a simple way to check if it’s acceptable to dose to the tank intentionally, as opposed to unintentionally, lol.

Perhaps we could compare bulk supply results.

I imagine an ICP test would give an idea. Can anyone describe a reliable method of obtaining a solution to send away and test? I’m thinking a saturated solution should be ok to have tested? Perhaps dissolving some with Hydrochloric and making a solution from that to include the normally precipitated stuff?

Thanking you muchly.

I did some ICP testing and give some specification purity data here:

Aquarium Chemistry: Magnesium And Strontium In Limewater

Because of a potential imbalance between the amount of magnesium and strontium used by corals, and the amount delivered by limewater, using limewater can potentially lead to depletion of both ions in aquaria.

reefs.com

 

[Garf]

I did some ICP testing and give some specification purity data here:

Aquarium Chemistry: Magnesium And Strontium In Limewater

Because of a potential imbalance between the amount of magnesium and strontium used by corals, and the amount delivered by limewater, using limewater can potentially lead to depletion of both ions in aquaria.

reefs.com

Fabulous.

So, if I were to do this;

“None of the samples were filtered, but all looked visibly clear.. The quicklime sample was made suspending 1 g of quicklime (Mississippi Lime Co. Vertical Calcium Oxide: CODEX (Food Grade) Pulverized Quicklime; Figure 1) in 1 L of deionized water. The sludge sample was prepared using 2.9 g of sludge (a mixture of water and solids) in 1 L of deionized water. The solid quicklime and sludge samples were acidified to pH 2 using reagent grade concentrated hydrochloric acid to be sure it all dissolved.”

That would be my starting point? And see what turns up on ICP?

 

[Randy Holmes-Farley]

Fabulous.

So, if I were to do this;

“None of the samples were filtered, but all looked visibly clear.. The quicklime sample was made suspending 1 g of quicklime (Mississippi Lime Co. Vertical Calcium Oxide: CODEX (Food Grade) Pulverized Quicklime; Figure 1) in 1 L of deionized water. The sludge sample was prepared using 2.9 g of sludge (a mixture of water and solids) in 1 L of deionized water. The solid quicklime and sludge samples were acidified to pH 2 using reagent grade concentrated hydrochloric acid to be sure it all dissolved.”

That would be my starting point? And see what turns up on ICP?

The only concern is how much the hobby icp companies have optimized their procedures for seawater and whether kalkwasser can give reliable results. I presume that folks who can test RO/di can test those, but it would be useful to tell them it is kalkwasser in case that impacts handling.

Maybe Christoph can advise.., @Christoph

 

[Christoph]

Hello!

Thanks Randy for tagging me to interesting questions

ICP is very matrix sensitive, since salt content changes viscosity (which changes nebulization/sample introduction). Aswell high matrix lowers plasma temperature and thus excitation pattern for different elements. This is why it is important to have matrix-matched standards.

Having a "freshwater sample" in an seawater optimized sequence (or the other way round) would give very unreliable data. In general it is important for the lab to know what to expect in a sample, otherwise the data will be unreliable and there is the risk of machine problems (and possibly damage).

We also do analysis of salts/raw materials, but it would be recommended to send us the solid (otherwise there might be contaminants from the water and dissolution progress). We can then dissolve the solid in lab grade water (+ nitric acid whenever required) and measured it on IC and ICP-MS. Due to the detection power of ICP-MS only very dilute siluations are required to get an accurate elemental profile (thus limiting matrix influence).

For the technically interested: We are furthermore using internal standards to correct for slight variations in dissolved solids/matrix, but this could never correct the gap between seawater/freshwater.

If you are interested in getting such an analysis done, you can PM me for details on the process and pricing.

all the best,
Christoph

 

[Garf]

Hello!

Thanks Randy for tagging me to interesting questions

ICP is very matrix sensitive, since salt content changes viscosity (which changes nebulization/sample introduction). Aswell high matrix lowers plasma temperature and thus excitation pattern for different elements. This is why it is important to have matrix-matched standards.

Having a "freshwater sample" in an seawater optimized sequence (or the other way round) would give very unreliable data. In general it is important for the lab to know what to expect in a sample, otherwise the data will be unreliable and there is the risk of machine problems (and possibly damage).

We also do analysis of salts/raw materials, but it would be recommended to send us the solid (otherwise there might be contaminants from the water and dissolution progress). We can then dissolve the solid in lab grade water (+ nitric acid whenever required) and measured it on IC and ICP-MS. Due to the detection power of ICP-MS only very dilute siluations are required to get an accurate elemental profile (thus limiting matrix influence).

For the technically interested: We are furthermore using internal standards to correct for slight variations in dissolved solids/matrix, but this could never correct the gap between seawater/freshwater.

If you are interested in getting such an analysis done, you can PM me for details on the process and pricing.

all the best,
Christoph

Thanks Christoph. I don’t think this needs to be super duper accurate, as I’m pretty sure nobody will know what you can and can’t get away with putting in the tank at really low levels. I really would like a simple “Under no circumstances put this rubbish in your tank” type gross test.
I’m gonna see what ICP tests the local LFS has got and give one of them a call, see what they suggest.

Cheers