KZ Coral Snow = Chalk?

[biom]

I was wondering what KZ Coral Snow is made of. It seems that it is pure natural chalk and water. I've made few simple tests and I'm pretty sure that it is chalk - it vigorously dissolves in acetic acid without residue, and after dehydration it looks exactly like chalk. I have natural chalk in hand and it is hard to find difference when compare with dehydrated Coral Snow. You can judge by yourself - on the picture attached - left is natural chalk and right is dehydrated Coral Snow, the stone is chalk.
Since chalk is almost pure calcite - Calcium carbonate with traces of Magnesium carbonate, silicates, ferric oxides,inorganic phosphates etc, I decide to give a try to pure calcium carbonate (analytical grade) instead Coral Snow - and it works like charm - it has the same effect, and I'm sure that there is no unwanted impurities like phosphates, silicates and ferric salts. The pure calcium carbonate is bright white, while chalk and Coral Snow have yellowish color, because of other salts.
I really like Coral snow because is helps a lot especially when new corals are added into the tank - the chalk reduces the mucus secretion from one side and coagulate organic compounds make them easily removed by skimmer or consumed by bacteria.
There are about 4 grams chalk in 10 ml of CoralSnow.

[bertoni]

Calcium carbonate particles might make a good flocculant, as you suggest. I hadn't thought of that application. So does it seem to make the water a bit clearer on average, or do you see effects only when adding new corals?

[biom]

Yes, it has similar effect on water transparency like activated carbon. Especially if there are yellowing agents in the water. But if you are using activated carbon, there will be no visible effect of course. After addition, water becomes milky but in few hours cloudiness disappear. I'm dosing weekly or biweekly.

[Mock]

Your OP kinda has me scratching my head though.

You said you used pure calcium carbonate (analytical grade) for your test and it worked like a charm.

Yet in the next sentence you mention just plain chalk and the color differences of it and the pure CC, as well as the Coral Snow.

Is it safe to assume you still havent used just a plain box of chalk and ran studies enough to come to a conclusion that it is safe to crush it and add it to the tank with no repercussions? What kind, brand, or anything else? Control, for testing and such?

[biom]

No, I'm not that brave to start testing chalk in my tank. As I mention chalk is natural rock and could have various impurities. The chalk on the picture is from quarry near by.
I don't think using chalk with unknown ingredients is good idea, because there are for sure phosphates, silicates and ferric oxides with unknown concentration in it. Probably the guys from KZ are made their home work and found a quarry with chalk of good quality with low phosphates and silicates. But still in my experience I found that frequent usage of CoralSnow causes diatom and green algae bloom on stones and glass, that's why I decide to switch to pure CC, so far so good.

[jedimasterben]

So, where is a good source of pure CaCO3?

[MetroKat]

Originally Posted by jedimasterben

so, where is a good source of pure caco3?

+1

[biom]

Hmm good question, I have it from my laboratory suppliers, I don't know how obtaining of analytical grade reagents is arranged in the US.

[Reefvet]

Originally Posted by biom

I was wondering what KZ Coral Snow is made of. ...

It's clay.

[biom]

Originally Posted by Reefvet

It's clay.

Could you please provide some arguments? I don't think it is a clay because the clay is hydrous aluminium phyllosilicate with various alkaline metals. Both aluminium oxides and silicates do not react with acetic acid, but CoralSnow dissolves completely with no residue even in 5% acetic acid, exactly like calcium carbonate.

[jedimasterben]

Just ordered a pound of food grade 97% calcium carbonate powder from Amazon. We'll see how it stacks up. Just wish I hadn't bought this 500mL bottle of the KZ stuff a couple weeks ago lol

[biom]

Originally Posted by jedimasterben

Just ordered a pound of food grade 97% calcium carbonate powder from Amazon. We'll see how it stacks up. Just wish I hadn't bought this 500mL bottle of the KZ stuff a couple weeks ago lol

That's good, now you can compare both. Keep us informed.

[MetroKat]

Originally Posted by jedimasterben

Just ordered a pound of food grade 97% calcium carbonate powder from Amazon. We'll see how it stacks up. Just wish I hadn't bought this 500mL bottle of the KZ stuff a couple weeks ago lol

i have 2 bottles. Sigh.

[downbeach]

I used to use it periodically as well. I always thought it looked like/wondered if it was Milk of Magnesia. Observation led me to believe it was beneficial to my system, and I know a few local reefers who I suggested trying it for a cyano problem and it seemed to have a good effect.

[biom]

Originally Posted by downbeach

I used to use it periodically as well. I always thought it looked like/wondered if it was Milk of Magnesia. Observation led me to believe it was beneficial to my system, and I know a few local reefers who I suggested trying it for a cyano problem and it seemed to have a good effect.

Did't compare it with Milk of Magnesia, but since Milk of Magnesia is Magnesium hydroxide with pH 10.35 I don't think this is the case, because I've measured the pH of CoraLSnow and it was 9 something (I have to check).

[tmz]

Originally Posted by biom

Yes, it has similar effect on water transparency like activated carbon. Especially if there are yellowing agents in the water. But if you are using activated carbon, there will be no visible effect of course. After addition, water becomes milky but in few hours cloudiness disappear. I'm dosing weekly or biweekly.

How much Calcium carbonate are you dosing per liter of aquarium water?

[biom]

Just like CoralSnow - circa 1 ml per 100 liters (25 gal) aquarium water. Since there are 3-4 grams calcium carbonate in 10 ml solution, that means about 0.4 grams calcium carbonate per 100 l water.

[tmz]

Thanks

[jedimasterben]

New tank is finally up and running and skimmer was broken in finally, so I did my first dose of CaCO3 last night. Pure white powder, I mixed probably 1/8tsp of the stuff into 100mL of water and dosed, it made the water look just like KZ Coral Snow does and this morning the light haze that the tank had was GONE. ****'s the real deal. $8.75 shipped for a pound (around 450ish grams) of 97% food grade CaCO3 powder from Amazon, a helluva deal compared to $120 for 400 grams (1 liter size) of the KZ stuff!

[jason2459]

Little bump of history with discussions around coral snow.

http://www.reefcentral.com/forums/sh....php?t=2098589

[agv180]

Which CaCO3 powder should I buy?

[aarozsps]

We reefers can make really pure calcium carbonate power by bubbling air through kalkwasser in water, just check the pH and when t goes below around 8-9 ish we know that almost all the hydroxide has reacted with the CO2 in the air.
Can do the same with magnesium hydroxide

[tmz]

That's an interesting idea for those who choose to use CaCo3 as a flocculant and transporter. Some of my friends use various commercial hobby grade flocculant products and seem to get improved polyp extension from their corals.

While , kalkwasser precipitates CaCO3 ; it also precipitates some impurities ;so the precipitant might not be " really pure calcium carbonate"; the purity of the precipitant depends on the purity of the calcium hydroxide(kalk) used to make the kalkwasser. I think when using the precipitant derived from food grade calcium hydroxide dosed in small amounts the amount of impurities will be very minimal, though.

This article has a good bit of detail:

http://www.advancedaquarist.com/issues/may2003/chem.htm

[jason2459]

If you removed the fully saturated limewater into another container away from what ever precipitated in the original mixing container then proceed with the above aeration wouldn't that be fairly pure as impurities had mostly already precipitated out into the mixing container ?

[bertoni]

Yes, if you remove the precipitates, the calcium carbonate that forms on aeration should be pure enough for our purposes.