Explain Kalkwasser to me like I am a 5 year old

[Novi]

I have read about Kalk, watched videos on it and I still do not understand it...LOL

I know it can raise your PH when dosing it. Thats the whole point of using it correct? Most dose in there water top off but that scares me. What if your top off were to stick, then you would have a Kalk overdose!

And if you have a refugium (Large enough one) and run an opposite light schedule on it to your DT so your PH doesn't drop at night, do you really still need to run Kalk?

[Big Country]

Kalk also doses equal parts calcium and alkalinity. You can have a kalk overdose, the trick there is to only put enough powder in the reactor to last a few days, that way even if things stick you won't have an overdose, maybe a flood if your refill water is large enough to overflow your system though, a problem with your salinity and a problem with your wife...lol. Light's on your refugium help with PH but my PH still drops around 0.2 every night on my system.

[Novi]

I always dosed for Calcium and Alk with E.S.V. B-Ionic 2 part. I love that stuff! Would I still need to dose with Kalk though? Probably not right because that would be overkill.

[BowieReefer84]

I also use b-ionic for alk and calc. It is my understanding "most" people start with kalk via ato, and when they are no longer able to keep up with the alk/calc demands of their tank they move to two part (or a calc reactor)...

 

You are just fine using two part only if that is working.

 

Here is a lengthy article explaining it much better....

http://reefkeeping.com/issues/2005-01/rhf/index.php

 

 

[Der ABT]

DONT TOUCH IT.....is that what yuo mean

 

basically explained above, i use vinegar to get more to dissolve... can be dripped or added with top off water.

check your alk often when dosing till yuo get a good schedule down.

 

i love the stuff and use it in conjuction with a CA RX

[Big Country]

I went from two part when I first started a reef, to dripping kalk out of one of those kent marine iv containers, to a kalk reactor when 2 part couldn't keep up with demand, to adding 2 part on top of kalk, to just hooking up my calcium reactor to use with my kalk reactor.

[zygote2k]

kalkwasser is calcium hydroxide. It supposedly is a balanced additive but in reality your tank uses alk and cal at different rates. A kalk reactor is just a container that keeps the kalk in solution and allows it to be dosed to the tank via an ATO or something similar. Since kalk makes calcium deposits, you can easily have a situation where float valves get stuck and cause a kalk overdose. In my opinion, you are far more likely to have better luck using a 2 part or 3 part dosing system. I've never had a cal or alk overdose with a doser, but I have seen the effects of a kalk overdose. (death).

Keep it simple.

[Origami]

I have read about Kalk, watched videos on it and I still do not understand it...LOL

I know it can raise your PH when dosing it. Thats the whole point of using it correct?

 

Not quite.

 

Kalk is a shortform for kalkwasser - German for Calcium-enriched water. It is a saturated solution of Calcium Hydroxide, Ca(OH)2. When added to your tank, it combines with ambient carbon dioxide (CO2) to release one calcium ion and two bicarbonate ions. These are used by your stony corals and certain algaes to form skeletons composed largely of calcium carbonate. The process of creating these skeletons consumes - yes, you guessed it, one calcium ion and two bicarbonate ions. That's why kalk is considered a balanced additive.

 

On the surface, this implies that your tank uses calcium and bicarbonate at a fixed ratio. However, there's a finer point in consumption that results in a very slight imbalance. Let me tell you why. It's mostly about magnesium.

 

The dominant ions in our tank are (in no particular order): Sodium (Na), Chloride (Cl), Calcium (Ca), Carbonates (CO2, CO3, and HCO3) - also known as alkalinity, Magnesium (Mg), Sulfate (SO4), and a host of other, lesser ions, including what we call "trace elements." In fact, our tanks are supersaturated with calcium and carbonates. (Supersaturated means that the ions are present in unnaturally high concentrations and should, as a consequence, precipitate out quickly, and naturally.) If it's supersaturated, then why don't the carbonates spontaneously precipitate? Well, it's largely due to the presence of Magnesium in the water. You see, if you were to look at the periodic table, you'd see that Magnesium is in the same column as Calcium. This means that the two atoms are related in their available molecular bonding structure and hence in the way they interact with other ions. In fact, the magnesium is so closely related that it sort of acts like calcium, forming an association with the carbonates in the water and interfering with their association with the calcium ions. This then results in the supersaturated condition.

 

Now, since the magnesium kind of looks like the calcium from a reactivity standpoint, our corals will incorporate magnesium into their bony structure incidentally, and in the place of a calcium ion. This happens at different rates for different corals. The end result is that, because magnesium is replacing calcium in some of the reactions, alkalinity is used slightly (sometimes very slightly) more quickly than the balanced amount of calcium delivered by a kalk stirrer.

 

This is not always the case with a calcium reactor. Because a calcium reactor dissolves coral skeleton material (containing magnesium), magnesium is automatically delivered by the device.

 

So let's touch base on your pH question. Kalkwasser raises the pH of your tank by converting the carbon dioxide (CO2) in your tank to bicarbonate (HCO3). The reduction in CO2 results in a drop of pH (since CO2 in water forms carbonic acid).

 

Raising pH is a byproduct of adding kalk. It is not normally the objective, though. Adding calcium and alkalinity is the reason that we add kalk.

 

Most dose in there water top off but that scares me. What if your top off were to stick, then you would have a Kalk overdose!

 

Many aquarists use kalk very successfully. But you need to be prudent about it and consider failsafes, and using good system design from the start. For example, never put more kalk in your reactor than can be used in a week. There are several threads here about the proper and safe use of kalk. I encourage you to look for them.

 

And if you have a refugium (Large enough one) and run an opposite light schedule on it to your DT so your PH doesn't drop at night, do you really still need to run Kalk?

 

As outlined above, kalk's primary purpose is not to shift the pH (you can do that with buffers if you really wanted to - for example, you could use borates), but to deliver calcium and alkalinity to the tank. A reverse light cycle on the refugium raises pH through photosynthesis - a process which consumes CO2 (hence raising pH) and releases oxygen. Many of our corals photosynthesize (using their zooxanthallae) during the daylight hours in our tank. That's why the pH goes up during the day, and down during the night (the diurnal pH swing).

 

Hope this helps lay it out for you.