Potassium level

[bubbaque]

what are acceptable potassium levels in a reef tank?

 

[biom]

390-400 ppm in NSW

 

[reefstacks]

I have a recent thread regarding SPS coloration, there is also some good info in there if you are interested in learning a bit more.

https://www.reef2reef.com/threads/sps-acros-best-coloration-what-elements-do-you-add.254944/

 

[Randy Holmes-Farley]

Here's my standard commentary on potassium:

Potassium

Potassium is listed with the less critical parameters, not because it isn't important, but due to the fact that it does not get rapidly depleted in most aquaria. The majority of reef aquarists do not test for or dose potassium, and likely have adequate amounts from water changes alone. Potassium is important for cellular function, and generally is higher in concentration inside of cells than outside. In people, for example, nearly all of it is inside of cells, with very low concentrations present in the blood.

In marine systems, most cells of organisms have higher concentration of potassium in them than the surrounding seawater. That would make it seem that potassium would be depleted rapidly as organisms grow and add tissue mass, whether they are bacteria, microalgae, macroalgae, fish, or corals. However, there is quite a lot of potassium in seawater and salt mixes, and aquaria are typically being feed foods that also consist largely of cells that once contained potassium. Assuming these cells are not broken open and rinsed free of potassium, a large amount comes in with foods. So the net concentration of potassium in the tank will be a balance between the food and other inputs, and the uptake from tissue mass (whether it is exported or left in the tank).

A number of aquarists have found their aquaria are depleted in potassium and dose it to maintain natural levels. I've not found it to be depleted in my aquarium and I do not dose any. Some people associate depletion with organic carbon dosing to drive bacterial growth, but I've not seen that in my system (perhaps due to the foods that I choose to feed). Of those with depleted potassium, the primary symptom seems to be certain issues with SPS corals such as Montipora. Sometimes it is reported as poor growth and/or greyish coloration. I do not know if that really does relate to low potassium, but if you have such an issue, measuring potassium with a kit and dosing if necessary may be useful. I'd recommend maintaining about 380-420 ppm, but if it already is higher than that level, I would not do anything to try to lower it.

 

[bubbaque]

I just received the salifert test and got a reading of 380. Seems to be within the acceptable range. Thanks!

 

[Queensreefer]

I dose potassium based on a weekly test and I have seen dramatic difference in blue color of my acros. I received a monti from a fellow Reefer that was white with green polyp. In my tank after 1 month it turned blue with vibrant green polyp. Maybe my potassium was optimal?

 

[Vamsi]

I dose potassium based on a weekly test and I have seen dramatic difference in blue color of my acros. I received a monti from a fellow Reefer that was white with green polyp. In my tank after 1 month it turned blue with vibrant green polyp. Maybe my potassium was optimal?

what is your potassium reading? do you test ?

 

[Randy Holmes-Farley]

what is your potassium reading? do you test ?

You realize that's an old post? :)

 

[Vamsi]

I didn't realize, till you have pointed it out Randy :). My potassium is 380, wondering if that is the cause of my greenish colored corals to be bit faded. Esp spongodes. Thank you Randy.

 

[Randy Holmes-Farley]

I didn't realize, till you have pointed it out Randy :). My potassium is 380, wondering if that is the cause of my greenish colored corals to be bit faded. Esp spongodes. Thank you Randy.

Doesn't seem very low, but it is not hard to raise it.

 

[Vamsi]

Thank you Randy.

 

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)