Potassium and SPS Corals

[Randy Holmes-Farley]

Anyone switched from instant ocean because of potassium deficiency? Please suggest and advice!

Normal IO has normal potassium. It is not deficient. :)

 

[haanstang]

Potassium works in conjunction with phosphate and nitrate. Kinda like alk and cal go together. So there should be a sweet spot. Say you have 0.5 po4 and 380 k. Your k will have a different effect on the tank than if your po4 is higher. I think that is why some people get away with a higher amount of k and others crash. I think you can get away with your potassium being higher than 400 if you phosphate is a little higher too. It has to do with the ratio not just the potassium. My 2 cents

 

[jda]

I test IO around 400 as well... on Salifert.

 

[Ashish Patel]

Normal IO has normal potassium. It is not deficient. :)

Thanks Randy!

 

[Ashish Patel]

I am assuming that with IO it will deplete overtime with small frequent waterchanges. I guess as the bio load increases could be good practice to hit them with few 30% waterchanges every 6 months.

 

[Randy Holmes-Farley]

Potassium works in conjunction with phosphate and nitrate. Kinda like alk and cal go together. So there should be a sweet spot. Say you have 0.5 po4 and 380 k. Your k will have a different effect on the tank than if your po4 is higher. I think that is why some people get away with a higher amount of k and others crash. I think you can get away with your potassium being higher than 400 if you phosphate is a little higher too. It has to do with the ratio not just the potassium. My 2 cents

I'm not convinced that is true. Unlike might be the case in a freshwater or terrestial system which are unusually low in potassium (say, 0.05 ppm or lower (1.3 uM or lower), ; see link below), I've never seen it mentioned in any literature that normal potassium levels are limiting to growth of any organism in full strength seawater. 400 ppm in seawater is a large amount of potassium (8000x the limiting level in freshwater).

Potassium-- A non-limiting nutrient in freshwater?
https://www.fba.org.uk/journals/index.php/FRJ/article/viewFile/149/240

 

[Randy Holmes-Farley]

I am assuming that with IO it will deplete overtime with small frequent waterchanges. I guess as the bio load increases could be good practice to hit them with few 30% waterchanges every 6 months.

It didn't in my case. I never added any potassium by dosing (only foods), and did 1% daily changes with IO. After years of this practice, a Triton test showed my system had 397 ppm:

My Triton Testing Results: By Randy Holmes-Farley
http://www.reefedition.com/my-triton-testing-results-by-randy-holmes-farley/

from it:

"Potassium (K). Many people are worried about potassium in their aquaria. About 4 ½ years ago, not long after I started using organic carbon dosing, I decided I should test to see if potassium was depleted in my aquarium. I compared my tank water to a true natural seawater sample and found about the same level in the standard as in my aquarium using a commercial test kit. The Triton result confirms that earlier conclusion: my aquarium is not becoming depleted in potassium despite skimming, growing macroalgae, and organic carbon dosing. Presumably, the foods and water changes are adequate to maintain the potassium level."

 

[Ashish Patel]

Randy.. Thanks for sharing your experience. I feed Larry's reef blend, mysis, and spectra pellets daily. What your potassium based food?.. I should probably get a lab test just to get a good idea of where my tank stands after 6 months. Hopefully I have similar findings but as you know everyone's tank is different as well as every batch of IO. I find it difficult bring out the blues and pinks in my corals so need to rule out potassium and other trace elements. However, its more then likely caused by my constant tinkering of things despite trying not to.

 

[crushedacro]

Im getting 270 on my salifert test kit for K with IO

 

[adtravels]

I use the salifert test kit, very reliable if instruction carefully followed.

When growing cheato strongly I found mine fell more rapidly arond 10-15 ppm per week.

when not growing cheato I find it stabilises and does not need dosing as frequently.

I dose ATI kalium (potassium) when levels are low

I keep mine from 380 to 410, any lower and my red robin pales out and I have not gone any higher than 410ppm

 

[Graffiti Spot]

An overdose of Potassium will burn new growth tips on SPS. Also, use a high quality ionically BALANCED Potassium product... straight KCl powder can be detrimental...

We've been using K in a number of our products for nearly 15 years... the importance of K is no surprise here.

What? How can KCI powder be detrimental? I know me and lots of people in my area who use it. What is an ionically balanced potassium product? How is this any different than using ice melter for magniesum? Just trying to learn here.

 

[aidz415]

I was dosing potassium for a while, but stop a few months back to see if I can get my Pink Floyds to yellow up. I never had burnt tips, but I heard or read somewhere that overdosing potassium can be seen on yellow coral. Instead of yellow you will start to get greenish hues.