Tunze 5074

[Duberz]

I got the calcium dispenser to use with my ato. Directions call for like 2 teaspoons a week which sounds way less than my usual 1 teaspoon/gallon. I must be missing something here?

 

[Midrats]

You load it up with kalk powder and top it up weekly as the powder dissolves.

 

[rvitko]

I take it you are using the example dosage for a tank under 48 gallons with only soft corals? The amount added is based on a 7 gallon reservoir and ranges from 2 teaspoons to 2 tablespoons. You will use less in a reactor as you have less loss to precipitation from exposure to CO2, in general kalkwasser is saturated at 1/2 to 3/4 teaspoon per gallon at typical room temperatures and the rest is lost to forming calcium carbonate from binding the CO2. The dosages are based on these saturation levels and the corals kept as well as trying to avoid adding powder slurry which can cause pH spikes. You will add more powder every time you refill the reservoir.

 

[mcarroll]

Check this out:
Measuring Kalk/Lime Reactor Output - Just Do It!

 

[rvitko]

Great input! Thank you!

 

[Duberz]

I started dosing kalk via the tunze calcium dispenser. I started with 4tsps in the container on 1/17. On 1/18 my alk was 9.895 and cal was 430,1/19 10.007 and 430,1/23 9.392 and 425,1/24 9.28 and 425. After 1/24 measurements I added 4 more tsps. That made a week between adding more kalk. Now today (1/26) I got 10.175 and 425. All measurements made by Hannah alk checker and salifert cal. My question is why is my calcium stable and alk is up and down?

 

[mcarroll]

Lots of things besides coral growth figure into alkalinity consumption and production within the tank, not the least of which are sediment and algae growth in the tank.

Plus there's a certain amount of error inherent to the tests.

 

[rvitko]

Kalkwasser is a very week supplement for Calcium so it is really not a significant source. What kalk does for alkalinity is primarily bind CO2 to form carbonate. As mcarroll stated, the biggest consumer of alkalinity will usually be organic acids formed by decomposing sediments. You also lose some to carbonic equilibrium over time and of course the corals utilize it for growth. Kalkwassers main advantage is helping to bind acids and phosphates in the system and increase pH, it is a very weak source of Calcium and typically will reduce the need for buffers and calcium but will almost never eliminate it.

 

[Duberz]

Do you think I need to adjust the amount of kalk I'm putting in the container or is the fluctuating alk I have considered stable?

 

[rvitko]

You should see a gradual increase in alkalinity over time, it will still have small variations but the trend should be a slow increase. I would not add more.