My Kalk is better than your Kalk!!!

[TD13]

So, I've been wrestling this Kalk dosing thing for a little bit now, and I'm new to dosing in general. It's got me thinking, is there a difference in the Kalk products that are available? Is one better than the other? More pure? More potent? Calling on the folks here that know... GO!

 

[redfishbluefish]

I don't use Kalk, but you've sparked my interest, so I'll be following along. Kalk is simply calcium hydroxide. I've got to believe the only differences you'd see from one brand to another is the grade or purity of this lime. I also have to believe that if it is being sold as kalkwasser, it is of sufficient grade. With that said, I know of people who go to WalMart and purchase pickling lime....which is food grade.

 

[TD13]

Pickling lime huh.... I sure hope people weigh in on this....

 

[Downbeach]

I started with Kent a long time ago, and have used the BRS I picked up from a tank break down. They all worked fine, but in the long run I preferred to use Mrs. Wages Pickling lime. I guess because it was food grade there was less "impurities" remaining in the bottom of my mixing containter, and less was tranferred into my ATO when I was using it there. The only draw back is that it isn't always available at Walmart or other big box stores, since its a seasonal item, and I started to order on line from Ace hardware.

 

[Randy Holmes-Farley Verified Community Expert]

There are two materials that can be used to make limewater (kalkwasser). Well, three, but calcium metal will likely cause a fire and is incredibly expensive.

The two are calcium oxide (CaO) and calcium hydroxide (Ca(OH)2). Calcium oxide is just dehydrated calcium hydroxide.

By weight, calcium oxide is more potent, but both make the same limewater if you add appropriate amounts. At saturation, the limewater is the same potency. I've used both and there's no difference except the CaO gets hot if you add it to a small amount of water.

As to brands, the only difference is likely to be the impurities present, and possibly the particle size (impacts dissolution rate, how it swirls in a reactor, etc.).

i do not know of any evidence that suggests any brand is any better than any other, but I'd use only food grades or pharmaceutical grades (or wateer treatment grade) as those are relatively inexpensive anyway. Pickling lime is a good grade calcium hydroxide and is just fine.

I discuss all of these issues and more here:
What Your Grandmother Never Told You About Lime by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-01/rhf/index.htm

 

[Pete polyp]

What about kalk+2 that has magnesium?

 

[jason2459]

What about kalk+2 that has magnesium?

Brightwell doesn't seem to know chemistry very well. I hope Kent fixes this.


http://www.advancedaquarist.com/2003/12/chemistry

 

[Randy Holmes-Farley Verified Community Expert]

What about kalk+2 that has magnesium?

Not useful and incredibly misleading. I am in a thread today where I detail how not useful it is:

https://www.reef2reef.com/threads/best-kalk-stirrer-brands-types.225280/

from those who do not care to switch to another thread, here's the short story:

1. Magnesium is not soluble in limewater, so it will just sit on the bottom

2. The amount present in kalk+2 (Brightwell claims 0.15%) is not nearly enough to meet the demand for magnesium based on that amount of calciuma nd alkalintiya dded (which might, however, be adequately met by water changes with a salt mix with plenty of magnesium).
3. The amount of magnesium in kalk+2 is LESS than is present in many bulk brands of calcium hydroxide as an impurity.

I did a calculation in that thread that, even if one ignores basic chemistry and incorrectly assumes all of the magnesium that Brightwell claims to be in the product gets into the tank water, at a dosing of 1% of the tank water volume daily using saturated limewater, the amount of magnesium added per day is too small to be noticed (0.02 ppm per day).

 

[Pete polyp]

Thanks! I was considering giving it a shot but I think I'll stick with Mrs. Wages for $3

 

[Randy Holmes-Farley Verified Community Expert]

Brightwell doesn't seem to know chemistry very well. I hope Kent fixes this.


http://www.advancedaquarist.com/2003/12/chemistry

Jack Kent (new owner of Brightwell) did recently remove the Guaranteed Analysis for Magnesion P when I recently wrote to him. That claim had been grossly incorrect (twice what the product actually contained) for many years. It was, incredibly, chemically impossible. But it was guaranteed!

 

[Josh King]

There are two materials that can be used to make limewater (kalkwasser). Well, three, but calcium metal will likely cause a fire and is incredibly expensive.

The two are calcium oxide (CaO) and calcium hydroxide (Ca(OH)2). Calcium oxide is just dehydrated calcium hydroxide.

By weight, calcium oxide is more potent, but both make the same limewater if you add appropriate amounts. At saturation, the limewater is the same potency. I've used both and there's no difference except the CaO gets hot if you add it to a small amount of water.

As to brands, the only difference is likely to be the impurities present, and possibly the particle size (impacts dissolution rate, how it swirls in a reactor, etc.).

i do not know of any evidence that suggests any brand is any better than any other, but I'd use only food grades or pharmaceutical grades (or wateer treatment grade) as those are relatively inexpensive anyway. Pickling lime is a good grade calcium hydroxide and is just fine.

I discuss all of these issues and more here:
What Your Grandmother Never Told You About Lime by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2005-01/rhf/index.htm

Randy, Thank you for your link to your lime article. I have printed it out and will put it in my binder with your other article on reef aquaria parameters. I'll give it a thorough read this weekend.

 

[redfishbluefish]

Randy, Thank you for your link to your lime article. I have printed it out and will put it in my binder with your other article on reef aquaria parameters. I'll give it a thorough read this weekend.

There will be a test on Monday. Please prepare accordingly.