Today on BRStv, we are going to go over kalkwasser also known as calcium hydroxide or hydrated
lime.
Kalkwasser is one of my personal favorite ways to maintain calcium, alkalinity and pH
in most low to medium demand or mixed tanks.
It's also one of the most affordable solutions.
In today's video we will discuss what makes kalkwasser an attractive solution, different
ways to dose kalkwasser to your tank, some basic precautions, a bit of science behind
how it works and finish with a few tips.
To me Kalkwasser is an attractive option because it raises calcium, alkalinity and pH all with
a single product and it does all this while being one of the most affordable solutions
available.
There isn't a single other product out there that even comes close in this regard.
It's also very easy for new reefers to use and understand.
It doesn't require a ton of expensive equipment or knowledge to get set up like a calcium
reactor does and it doesn't require the use of multiple products like two part.
For many people it is also the only way they will ever raise their pH consistently into
the 8.2 to 8.3 range.
Kalkwasser comes in a powder form and should never be added directly to the tank.
You first mix it with purified freshwater and saturate the solution.
The liquid will be cloudy at first but will eventually settle out over the course of a
few hours.
It is the clear solution we want to dose which is sometimes referred to as saturated lime
water.
You should avoid dosing the powder that settles out at the bottom because it can contain impurities
and will likely raise your pH to an undesirable level.
Because the saturated solution raises the pH so quickly it is important to dose it rather
slowly.
Typically over at least a few hours but often longer.
There are a few ways to do that.
The first is to build yourself a quick do it yourself dripper which is just a jug with
a small valve to control the drip rate.
This is probably how a lot of people are first introduced to dosing kalkwasser.
It's fairly simple, build one that's sized to your tank, ideally it should hold enough
kalkwasser solution to fulfill your tanks calcium and alkalinity needs for a day and
not be larger than your tank would evaporate in a day.
Just start the drip whenever you do your other daily maintenance like feeding the tank.
Most people will have two so they can mix the following day's solution at the same time
and give it plenty of time to settle out before using it.
You can also get a slow dosing pump and a timer which will trigger the pump to turn
on and off.
However the method I personally like the most is coupling kalkwasser with an auto top off
system which automatically replaces the evaporated water.
This means you have a single solution solves a few fairly major tasks, maintaining calcium
and alkalinity, elevating pH and replacing evaporated water.
The beauty of using the auto top off system for this is evaporation naturally happens
at a fairly slow rate so this can be an ideal way to make sure the saturated kalkwasser
solution is added very slowly as well.
One word of caution here - you will want to use a high quality auto top off system you
trust.
It can be a fairly big disaster if your top off system fails on and dumps a large volume
of kalk solution into the tank because the pH will skyrocket.
My personal favorite is the Tunze Osmolator primarily because it is one of the few that
has never failed me in the on position but also because I really like that it uses two
different technologies to measure the water level.
The first is an electoral eye that has no moving parts to get stuck and the backup level
sensor is a common float switch.
I also like the Elos Top Off for similar reasons the small probe works off temperature and
doesn't have any moving parts.
It also has a backup mechanism programmed into it which limits the volume of water added
to the tank and will likely avoid a major disaster.
One of the nice things about the Elos unit is how low profile the whole thing is.
This tiny probe can fit in basically any sump and in my opinion the best solution for tanks
without a sump.
If you are running an inexpensive auto top off that uses only float switches which can
and will eventually stick or just looking for another level of security you can always
add a stand-alone pH controller or complete aquarium controller to the system and set
it to turn the auto top off system off if the pH ever gets too high.
This is a good idea, even if you have two float switches.
Keep in mind that the things like salt creep, power surges and rogue snails which can make
one switch fail can make the other switch fail as well.
Another method of adding kalkwasser is with a reactor or stirrer which are somewhat similar.
With both of these you add a bunch of kalkwasser to the bottom and mix the kalk with freshwater
to be slowly added to the tank.
The primary advantage of using a reactor over a simple reservoir is you can hold a healthy
amount of kalkwasser in a small amount of space and ensure it is always completely saturated.
It also limits the amount of carbon dioxide the kalkwasser comes in contact with which
will help maintain potency.
Reactors tend to use pumps to mix the solution which works but has a few down sides.
The pump will rapidly mix the kalk and water into a into complete kalkwasser slurry which
is ok but you will have to wait a few hours for it to settle out, you don't want to dose
that slurry to the tank.
This means you will have to implement a series of timers to occasionally mix the kalk as
well as turn the feed pump on and off so it is never be on within a few hours of the last
mixing cycle.
Most people find this fairly undesirable.
I'd also like to note that most mixing pumps that operate in a solution of kalkwasser will
rapidly become covered in precipitate so they require frequent maintenance or replacement.
Stirrers work a bit differently, rather than rapidly mixing the kalk with a pump they use
a slow moving stir bar which just keeps the bottom slightly moving.
The feed pump pumps water through the bottom so it has to pass through the portion that
is mixing and insures that it is fully saturated.
Beauty of this is it shouldn't require any timers because only the very bottom of the
reactor is ever filled with the slurry.
The only time the slurry should ever hit the top and enter the tank is if you are using
too fast of a pump or too small of a stirrer for your size tank or typical evaporation.
One thing to note about both stirrers and reactors is you can't control the potency
of the solution, more or less it will always be fully saturated and at full strength.
With the dripper we mentioned earlier it is easy to add less kalk to the solution when
you mix it up to control the potency of the solution.
Keep in mind that two teaspoons is the maximum amount that will dissolve in a gallon of water.
As with everything there are a couple downsides, first is the powder is fairly caustic, talc
like and easy to blow around.
Most manufacturers will tell you to wear gloves, goggles and a mask when handling it.
It absolutely isn't the type of thing you want to breathe in or get in your eyes because
it will burn.
Depending on how sensitive your skin is you might have issues there as well.
Before using checkout the manufacturer's safety suggestions.
The desirable effect of raising the pH is also a factor which limits how much you can
add in a single day because we don't want the pH to go much over 8.3 so you might outgrow
this solution when your tank becomes fairly heavily stocked.
You can also be limited by the amount of water your tank evaporates.
If your tank evaporates a half gallon a day that's also the maximum amount of saturated
kalkwasser solution you can add as well.
There are, of course ways to increase the amount of evaporation but excess moisture
can cause a variety of issues with your home and it might just be better to switch to a
different calcium and alkalinity solution if your tank outgrows this one.
Time to include a little bit of science on how kalkwasser works . Almost every other
product out there that claims to be able to add calcium and alkalinity with a single product
is just calcium carbonate in a bottle which more or less is just pulverized sand.
Since calcium carbonate doesn't dissolve in our tanks at normal pH ranges of 7.8 to 8.3
most of these products are of low value.
Kalkwasser is different from all of these products and I believe the best one bottle
product that can effectively raise calcium and alkalinity in amounts useful to most reef
tanks.
Any product labeled kalkwasser is really just calcium hydroxide also often referred to as
hydrated lime.
Kalkwasser is a German word referring to the saturated solution you get when you mix the
kalk with freshwater.
Kalkwasser or calcium hydroxide is produced by heating calcium carbonate to over 1500
degrees which liberates the carbon dioxide and produces calcium oxide.
A small amount of water is then added to produce calcium hydroxide or hydrated lime and known
to the aquarium industry as Kalkwasser.
What makes this such a cool product and different from
those which attempt to dose calcium carbonate directly is when you mix it with fresh water
the calcium hydroxide ionizes into separate calcium and hydroxide ions.
This obviously adds calcium but when hydroxide combines with carbon dioxide in the tank it
produces components of alkalinity like carbonate and bicarbonate which our corals will use
in conjunction with the free calcium ions to build their calcium carbonate skeletal
structure.
The beauty of this is it adds these elements added in a natural, balanced manor and at
the same time effectively removes carbon dioxide from the tanks water which raises the pH,
something basically all of us would like.
A few last tips on using kalkwasser.
Interaction with carbon dioxide in the air and water will reduce the potency of the solution
and even powder itself so for that reason it is important to store the dry product with
the lid tightly secured.
If you mix and store the fluid in a large container it is a good idea to put a lid on
the container to minimize gas exchange.
However, a thin crust will likely form on the surface which will protect it to some
degree as well.
When mixing just give it one good vigorous mix and let the powder settle.
You don't want to use pumps or air stones to mix the water after that because it will
just add unwanted carbon dioxide and reduce the potency of your kalk solution.
Lastly while kalkwasser is a great tool to replace the small amounts of calcium and alkalinity
consumed by your corals each day, it isn't a very good tool to make large adjustments
because you can't add enough to make a big difference without raising the pH too much.
Most reefers will adjust the calcium and alkalinity levels to where they want them using calcium
chloride and sodium bicarbonate or their favorite two part additive because it is possible to
add more of these in a single dose without effecting the pH significantly.
They then use kalkwasser to maintain these new levels on a daily basis as the corals
consume small amounts each day.
That about wraps up today's episode.
This week's question of the week is "What is your favorite auto top off system and would
you consider using it with kalkwasser?"
Next week we are going to do an in depth episode on two part as well as a short video on calibrating
your dosing pump.
If you would like to be notified when these come out hit that subscribe button.
Thank you for watching BRStv.