[Pomme]

is kalk needed?

i have got a 100 gal reef tank with a few softies and some hard corals, i am at the moment adding the kent liquid calcium at 30 ml a week. but i am sure that this will go up as soon as the corals start to grow and the calcarious algae starts.

so i was wondering what you guys thought the best way to add calcium to the tank was, eg, the kent additive, kalk or a ca reactor?

with the kalk is the only benefit of it the ca or are there others?
and whats the best way to add it?

thanx andrew

[Ninong]

Kalkwasser is a balanced additive that maintains both calcium and alkalinity. It has the added benefit of precipitating phosphate.

Two part additives, such as B-Ionic or C-Balance, are another method of adding both calcium and buffer but they are more expensive than Kalkwasser and they do not precipitate phosphate.

A one-part calcium additive (calcium chloride) is fine for occasional use to boost calcium levels but it should not be used on a regular basis because it will throw the chloride ions out of balance eventually.

Use either Kalkwasser or a two-part system to maintain calcium levels. If the calcium level is too low, then use extra calcium chloride (or extra calcium component of the the two-part additive) to raise the level up to your desired range and then maintain it at that level with either Kalkwasser or a balanced two-part additive.

kalkwasser?

[Poseidon]

Don't know if you can find it so easy on your side of the pond, but "pickling lime" from the grocery store is Calcium Hydroxide, one of the main components of Kalk, you can also use baking soda Sodium Bicarbonate for pH balance, and in another thread Epsom Salt is used for Magnesium supplementation...

[Ninong]

Originally Posted by Poseidon

Don't know if you can find it so easy on your side of the pond, but "pickling lime" from the grocery store is Calcium Hydroxide, one of the main components of Kalk, you can also use baking soda Sodium Bicarbonate for pH balance, and in another thread Epsom Salt is used for Magnesium supplementation...

Just a minor correction but calcium hydroxide is the ONLY component of Kalk. The only difference between pickling lime and the "Kalkwasser" sold for the reef aquarium hobby is in the grade. Both are pure calcium hydroxide; one is food grade and the other is lab grade.

[Pomme]

cool i may see if i can get some of those

[Pomme]

ohhh and whats the best way to add the kalk, or pickling lime, is it good in a reactor or just a bottle and drip it in?

[Ninong]

Originally Posted by Pomme

ohhh and whats the best way to add the kalk, or pickling lime, is it good in a reactor or just a bottle and drip it in?

If you don't have a Kalkreaktor, you can do as I do: kalkwasser?

I drip it in overnight to help balance out my pH swings. It usually takes about 8 hours to dose 2 gallons at the drip rate that I have. I use one of those cheapy 2.5 gal Kent Aquadosers but you can probably make your own.

[Pomme]

what procedure do you use for the kalk mixture, how mant rable spoons to how much water, do you discard any, as much info as possible please?

[Ninong]

Originally Posted by Pomme

what procedure do you use for the kalk mixture, how mant rable spoons to how much water, do you discard any, as much info as possible please?

I like to make up a fresh batch every day. I usually make up 2.5 - 3 gallons of limewater even though I know that I will only use about 2.25 gallons at the most.

I put 3 gallons of purified freshwater in a 4.5-gal white plastic bucket. I then add 2 level tablespoons of calcium hydroxide powder (Kalkwasser powder or pickling lime). I stir with a large white plastic spoon until it dissolves. I cover the bucket with the lid and wait a few hours (or several hours) until the solution is crystal clear. Then I carefully pour the clear liquid into my Kent Aquadoser being careful not to shake up the bucket. You want to leave the cloudy precipitated stuff at the bottom of the bucket.

You can either discard the cloudy precipitate at the bottom of the bucket after each batch or you can leave it for a couple of times and just add more freshwater and more calcium hydroxide powder for your next batch. You should NEVER add the cloudy stuff to your aquarium because it contains other precipitates besides just calcium carbonate.

How much calcium hydroxide powder you use is up to you but the maximum that will go into solution (without the help of vinegar) is two teaspoons per gallon of water. That's why I use two tablespoons (6 tsp) of powder with my three gallons of water. If you want to save money, try just 1 tsp/gallon of water until your tank has more calcium demanding corals and stuff in it. Right now I'm using 2 tsp/gallon of water. Once my tank has a lot of stuff in it I will probably move that up to 1 Tbsp/gallon of water with a little vinegar added to the water. I will probably start out with just 1 Tbsp of vinegar per gallon of water along with 1 Tbsp of calcium hydroxide powder per gallon of water. You should not use more than 3 Tbsp of vinegar per gallon of water. Remember, you don't need any vinegar at all as long as regular strength Kalkwasser is doing the job.

[Pomme]

cool thanx very informative just what i wanted, thanx

[Poseidon]

Perfect timing Ninong, I finally found the Pickling lime at a Meijers (kinda like Walmart with groceries) and was ready to start adding the Kalkwasser myself.

I'm curious though, how does CaOH also maintain Carbonate hardness? I know it does, but how can the Hydrogen and Oxygen raise the Alk?

[Poseidon]

Nevermind the article Kevin posted in another (very similar) thread answered my question... Atmospheric C02 never would have figured it could effect the solution. I thought Co2 was relativley stable, and not really looking to react with anything else.

[Ninong]

Originally Posted by Poseidon

I'm curious though, how does CaOH also maintain Carbonate hardness? I know it does, but how can the Hydrogen and Oxygen raise the Alk?

When you dissolve Ca(OH)2 in water you get Ca++ + 2OH-. This is what we call Kalkwasser (or limewater in English). It has twice as many negative hydroxide ions as positive calcium ions. The hydroxide ions cause the pH to go up, giving saturated limewater a pH of 12.4.

When you drip this saturated limewater (Kalkwasser) into your aquarium you are adding Ca++ ions which are essential to the calcium demanding organisms in your aquarium but you are also adding a lot of hydroxide ions. The OH- neutralizes a lot of the organic acids which would otherwise exhaust its buffer capacity and, as lagniappe, you precipitate those nasty phosphate ions. In addition, the calcium ions and hydroxide ions will react with free carbon dioxide (from the atmosphere) as follows: Ca++ + 2OH- + CO2 --> Ca++ + CO3-- + H2O. This last bit is also why you do not want to let your Kalkwasser sit around for a long period of time exposed to the air because it will eventually become supersaturated, calcium carbonate (CaCO3) will precipitate, causing the pH as well as the carbonate hardness and calcium concentration to go down. For example, freshly prepared saturated Kalkwasser has a pH of 12.4 thanks to the high amount of OH- ions, it has 900 mg/L Ca++ ions and high carbonate hardness but if the pH is allowed to drop to 10, the Ca++ ions will drop from 900 mg/L down to around 5 mg/L and there will be almost no carbonate hardness at all.

[Pomme]

how long does it take to do get supersaturated? is it longer in a reactor?

[Ninong]

Originally Posted by Pomme

how long does it take to do get supersaturated? is it longer in a reactor?

I don't know the answer to that question but according to Randy Holmes-Farley's testing it took only 10 hours with an airstone running in the container and an undisturbed container showed little degradation even after 20 days. Fossa & Nilsen make the claim in volume one of their series that periodic stirring, as in a Nilsen reactor, prolongs the length of time that Kalkwasser solution is "fresh" compared to an unstirred container. Randy says that there is no evidence to support that claim.

The short answer is that you will have to replenish the Kalkwasser in your reactor long before it goes bad anyway.

[Poseidon]

Thats what Ninong answered in another thread about how long does kalk last and thats what the article I sent you explains as far as the reactor goes. The principle for the reactor was to keep the Kalk from being exposed to air. The link above shows how that did not work in reality as well as in theory. And as you can see from Ninongs awesome explanation, Kalk that is left exposed to the atmosphere for too long becomes useless....

So my chemistry teacher was right, I do NEED to know how this stuff works

[Wind]

ya i was wondering how long i should wait before i drip.. can i mix it a few hours in advance and dose it at night..

can i use those plastic 1 gallon milk container? is it okay?

[Ninong]

Originally Posted by Wind

ya i was wondering how long i should wait before i drip.. can i mix it a few hours in advance and dose it at night..

can i use those plastic 1 gallon milk container? is it okay?

Yes, you can use one of those 1-gal plastic milk containers to drip the Kalkwasser as long as you mix it up in something else first and let the precipitate settle to the bottom before pouring off just the clear liquid into the dripping container. You should mix it at least three or four hours in advance before pouring it into the dripping container. I usually mix mine in the morning about 10 hours before using it.

[Pomme]

cool thanx for the replies just wanted to make sure everyone had the same ideas, sorry!

i understand how to use it now thanx guys for all you help,
tahnx
andrew

[jdepp]

whats the vinegar for? also what would happen if the white milky kalk mix got into the tank?