Potassium Dosing - 3 x NSW Level

[Scrubber_steve]

In this 2014 MACNA presentation Justin Credabel talks about dosing potassium to obtain levels 2 to 3 times higher than natural sea water levels, & along with iron dosing gives his corals faster growth & more color.



Discuss

 

[Randy Holmes-Farley]

Interesting.

 

[Alfrareef]

Following...

 

[Alfrareef]

I can give it a try.
When Potassium is low my montis (encrusting) start looking grey, so I can use them as a gauge and lets see what happens.

 

[Scrubber_steve]

I'm curious as to how elevated potassium would increase the rate of growth & color?

Is this just an anecdotal observation by a couple of hobbyists? Or is there some science to back up this hypothesis?

 

[rkpetersen]

And I just got my potassium level back down to normal, too.

 

[Scrubber_steve]

Seems the basis for an elevated level of potassium is to keep a balance with the other fertilizers in the water - nitrogen & phosphorus.
The hypothesis is that aquariums typically have higher levels of N & P than the ocean, & as potassium is also a necessary element for photosynthesising organisms, just as N & P are, it too should be elevated.

 

[gregkn73]

Once I accidentally overdose,and lost shrimps and some acros and montis. So if you raise K levels, do it slowly.

And I remember Triton boss , in a macna talk, mention not to worry about high K levels.

 

[Stigigemla]

As a fertilizer there will never be to low potassium level in a reef tank. Potassium is normally about 400 mg/l in seawater and the consumption is about of the same level as phosphourus.

But potassium has another function in animals as regulation of the flow through ion channels in cell walls. I have not seen any data on how sensitive animals are for low or high levels exept for human beings. I believe we should have about 8 mg/l in the blood but I guess saltwater fishes have a quite different level and the animals with seawater as a body fluid different again.

 

[gregkn73]

As a fertilizer there will never be to low potassium level in a reef tank. Potassium is normally about 400 mg/l in seawater

So you are saying, as an example, that if K level, reduced to 200mg/l, there won't be any negative effect to our reef inhabitants?

 

[Stigigemla]

No I dont say that. I guess it wont change much of the way algae are living in the tank. But it certainly will change the way corals live. And maybe it will affect fishes too.
I have seen losses in coloring and growth of corals with a potassium level of 320. But the algae grew on as usual. The corals regained their colors in about a week after raising the potassium to 400.

 

[gregkn73]

No I dont say that. I guess it wont change much of the way algae are living in the tank. But it certainly will change the way corals live. And maybe it will affect fishes too.
I have seen losses in coloring and growth of corals with a potassium level of 320. But the algae grew on as usual. The corals regained their colors in about a week after raising the potassium to 400.

I totally agree, but why did you wrote the first paragraph, I quoted earlier?

PS in low levels of potassium I notice slow to very slow, growth of chaeto in refugium and algae on ATS.....but the point here , is high levels of potassium.

 

[Scrubber_steve]

Spoke to Sallstrom about this after reading one of his posts in his thread -

"New for us, dipping Acropora corals in tank water with extra potassium. Raised the K from ca 400ppm to ca 1600ppm. Dip is going on right now. Starting with 20 minutes.
Testing with 6 different species of Acropora"
&
"Okey. First impression. 5mm Gammarus amphipods were dead/stunned after just a couple of minutes. A Asterina seastar dead after 20 minutes. So it kills/stun stuff for sure. I couldn't find any AEFW, but that might just be because the corals were dipped a couple of month ago and the flatworms hasn't returned. This was mostly a test to see how the corals react after a treatment. The corals did release some musus/slime.
Now they are all back in the propagation tanks where they were before. Will check on them to see if they were affected bad by the dip."

 

[hart24601]

I asked him in person about it and testing and he said he didn't even test - just adds a lot and seems to notice a difference! I'm sure he tested it before to ballpark those numbers but was surprised by his answer.

 

[gregkn73]

Sallstrom and others notice killing of invertebrates . That may be not be only an effect of the rise*3 level of K ,but also of the speed of rising to that level.....Triton boss and the macna speaker are very knowledgeable and so increased levels of K may not harm anything , if K concentration ,rises gradually. As I wrote , I also noticed negative effects by increased K levels, but I had also dump a big quantity of K, instead of rising it slowly.