Starting kalk dose?

MIke Wood · Mar 6, 2024

Randy Holmes-Farley said:
Adding kalkwasser creates a CO2 level in the water that is lower than was there before you added it, which raises pH. A skimmer allows the tank to pull in CO2 from the air faster:

Ca(OH)2 --> Ca+ + 2OH-

OH- + CO2 --> HCO3-

So if i am using a Skimmer specifically for gas exchange and increase my ph. would it be best to remove the skimmer all together if running kalk? But again my kalk dose is only .4dkh per day.

Randy Holmes-Farley · Mar 6, 2024

MIke Wood said:
So if i am using a Skimmer specifically for gas exchange and increase my ph. would it be best to remove the skimmer all together if running kalk? But again my kalk dose is only .4dkh per day.

I would not remove a skimmer to try to raise pH. It gives up several benefits (oxygenation and organic matter export). Depending on the kalkwasser dose, removing it may reduce the pH at night.

CloudReefer · Mar 6, 2024

Randy Holmes-Farley said:
Adding kalkwasser creates a CO2 level in the water that is lower than was there before you added it, which raises pH. A skimmer allows the tank to pull in CO2 from the air faster:

Ca(OH)2 --> Ca+ + 2OH-

OH- + CO2 --> HCO3-

So then would it follow that if one is having low pH issues due to high CO2 then running without a skimmer would help reduce the CO2 levels in the water due to less gas exchange overall?

I ask because the water will try to roughly equalize the CO2 levels with what is in the atmosphere right? So without a skimmer, the CO2 levels would adjust up or down more slowly?

I'm just curious about how all this works. My pH stays around an 8.15. I live alone with a cat so CO2 not much higher than 400ppm at my place.

Randy Holmes-Farley · Mar 6, 2024

CloudReefer said:
So then would it follow that if one is having low pH issues due to high CO2 then running without a skimmer would help reduce the CO2 levels in the water due to less gas exchange overall?

I ask because the water will try to roughly equalize the CO2 levels with what is in the atmosphere right? So without a skimmer, the CO2 levels would adjust up or down more slowly?

I'm just curious about how all this works. My pH stays around an 8.15. I live alone with a cat so CO2 not much higher than 400ppm at my place.

Skimmers drive the CO2 level in the water toward equilibrium with the air entering it.

Depending on the air CO2 level and the existing tank pH, that may raise or lower pH, and it may even raise the pH at night while lowering it during the day, even on the same tank.

CloudReefer · Mar 6, 2024

Randy Holmes-Farley said:
Skimmers drive the CO2 level in the water toward equilibrium with the air entering it.

Depending on the air CO2 level and the existing tank pH, that may raise or lower pH, and it may even raise the pH at night while lowering it during the day, even on the same tank.

Much better said than me! lol

Thanks!

ESABOE · Mar 6, 2024

Randy Holmes-Farley said:
Skimmers drive the CO2 level in the water toward equilibrium with the air entering it.

Depending on the air CO2 level and the existing tank pH, that may raise or lower pH, and it may even raise the pH at night while lowering it during the day, even on the same tank.

Ok, way past my lvl of understanding. I intended on using BRS kalk powder in a jug. My tank is in my bedroom, but I keep window cracked at night for carbon dioxide issues.

Randy, I wasn’t sure if you said I could run kalk without skimmer but just need to monitor PH? Which I do weekly through testing

Randy Holmes-Farley · Mar 6, 2024

ESABOE said:
Ok, way past my lvl of understanding. I intended on using BRS kalk powder in a jug. My tank is in my bedroom, but I keep window cracked at night for carbon dioxide issues.

Randy, I wasn’t sure if you said I could run kalk without skimmer but just need to monitor PH? Which I do weekly through testing

You can use it without a skimmer. Just make sure in the first couple of days that pH does not get too high.