High Potassium Levels in My Reef Tank

[David S]

Hi Everyone

A little background first:

I have a longstanding Reef Tank for which I had been dosing Potassium Chloride to maintain K levels
at ~420 PPM. Whenever I was negligent and failed to dose the K levels in the tank would fall to 350 PPM
or less.
At some point, about a year ago, I stopped dosing KCL as my K levels were approaching 500 PPM
Since then my levels have been consistently in a range of 440 - 460 range as measured by my Salifert test kit and ICP results.
While these are not alarmingly high levels, I would like to see them lower. Furthermore, I'm puzzled why the Potassium is staying high when I no longer dose it.
I do dose various elements, as per Reef Moonshiners. Among them is Seachem's Reef Iodide for Iodine supplementation. It consists of Potassium Iodide, but what I learned from a previous thread is the amount of Potassium that is added to the tank is negligible.
Can anyone think of any elemental supplements that may have sources of Potassium that may lead to my elevated levels?
Thank you

 

[taricha]

All my measurements (some calibrated against homemade standards) of potassium in my tank put it around 450, with no supplementation.

In this thread, a decent number of salts were found to mix up to K values in the 420-450 range right out of the bag.

The Ultimate Salt Test

I wanted to get this thread up and going before the holidays soak up all my time. I did a live YouTube with Deven from ReefDudes going over things but it is about 1.5 hours long. I will write up a more detailed explanation here in this first post soon. I am a hobbyist first and foremost. I have...

www.reef2reef.com

 

[David S]

All my measurements (some calibrated against homemade standards) of potassium in my tank put it around 450, with no supplementation.

In this thread, a decent number of salts were found to mix up to K values in the 420-450 range right out of the bag.

The Ultimate Salt Test

I wanted to get this thread up and going before the holidays soak up all my time. I did a live YouTube with Deven from ReefDudes going over things but it is about 1.5 hours long. I will write up a more detailed explanation here in this first post soon. I am a hobbyist first and foremost. I have...

www.reef2reef.com

WOW and thanks.
So the undisputed Champ for Potassium appears to be ESV.
It just so happens that has been my salt of choice for the past year!
Strange, though, because it surprises me that with a 10% weekly water change I would expect the concentration to drop over time.
(I have seen it as low as 430 and perhaps that is when I haven't changed the water for awhile.)
At least now I know what is driving my Potassium.
While it is high I can live with it, especially since there's a limiting factor.
In the meantime, I'll abstain from water changes for a week or so and see what happens.

 

[David S]

WOW and thanks.
So the undisputed Champ for Potassium appears to be ESV.
It just so happens that has been my salt of choice for the past year!
Strange, though, because it surprises me that with a 10% weekly water change I would expect the concentration to drop over time.
(I have seen it as low as 430 and perhaps that is when I haven't changed the water for awhile.)
At least now I know what is driving my Potassium.
While it is high I can live with it, especially since there's a limiting factor.
In the meantime, I'll abstain from water changes for a week or so and see what happens.

Wait a second; I use a high salinity concentration for my replacement water.
So that would raise the Potassium level even further.

 

[Randy Holmes-Farley]

How are you measuring potassium?

There’s no reasonably fast way to lower it except by water change with a lower potassium mix.

 

[David S]

How are you measuring potassium?

There’s no reasonably fast way to lower it except by water change with a lower potassium mix.

Using Salifert.
And will be adding small amounts of TLF Accurasea1, occasionally, to maintain salinity.
Of course, I don't know the K content in Accurasea. Hope it's less.

 

[taricha]

Wait a second; I use a high salinity concentration for my replacement water.

Yeah. I forgot to give the caveat.
Half of the instances of " _____ major element is too high" are really - salinity is elevated. So check salinity before deciding a major element is actually high.
If your salinity is 5% or 10% high - then your K would measure 20ppm or 40ppm high.

 

[David S]

Yeah. I forgot to give the caveat.
Half of the instances of " _____ major element is too high" are really - salinity is elevated. So check salinity before deciding a major element is actually high.
If your salinity is 5% or 10% high - then your K would measure 20ppm or 40ppm high.

Well I measured my Potassium earlier today and in spite of not doing any water changes since Monday, my Potassium as measured by Salifert, still comes in at 450 PPM.

Really mysterious, as for years I have dosed KCL to keep my K level above 400 PPM.

I will be sending in an ICP test next week and we will see what happens.

Actually, it will be two ICP's; one Triton and one Fauna Marin, but that will largely be part of another thread.

 

[David S]

Well I measured my Potassium earlier today and in spite of not doing any water changes since Monday, my Potassium as measured by Salifert, still comes in at 450 PPM.

Really mysterious, as for years I have dosed KCL to keep my K level above 400 PPM.

I will be sending in an ICP test next week and we will see what happens.

Actually, it will be two ICP's; one Triton and one Fauna Marin, but that will largely be part of another thread.

Ok so I sent in my ICP's last week.
The Triton ICP is currently in limbo, courtesy of USPS, but I received the Fauna Marin results earlier today. (In 7 days not bad).
Anyway, my result from Salifert, taken in conjunction with the ICP was ~440 PPM, the Fauna Marin result was 443 PPM.
So Potassium remains high - for whatever reason. But as long as it doesn't deviate, I'm OK with it.

 

[Randy Holmes-Farley]

Ok so I sent in my ICP's last week.
The Triton ICP is currently in limbo, courtesy of USPS, but I received the Fauna Marin results earlier today. (In 7 days not bad).
Anyway, my result from Salifert, taken in conjunction with the ICP was ~440 PPM, the Fauna Marin result was 443 PPM.
So Potassium remains high - for whatever reason. But as long as it doesn't deviate, I'm OK with it.

IMO, 440 pm is not a concern.

 

[David S]

IMO, 440 pm is not a concern.

Thanks Randy