Potassium test kit

[graveyardworm]

I've been communicating with Habib from Salifert alittle bit about putting together a potassium test kit. I've been dosing KNO3 and am wondering what the K levels look like. I'd like to know if its being used or just building up in the water. If anyone could provide some info regarding K and its use in marine aquariums it would be greatly appreciated. I've done an RC, and Google search, and there doesnt seem to be alot of fact based info.

 

[Samala]

David, here's an old thread on potassium that is a start.

If you look at Randy's What is Seawater? RK article you will find ratios of the three major electrolytes in seawater; Na 10,500ppm, Ca 410 and K 385. That puts potassium naturally at about 3% of the total of those three, there are other ions in the mix of course. I would suppose we might get concerned about running out, but I'm still wondering just how a potassium overdose would show itself.

In freshwater aquatics, K deficiency shows up as yellowing of the leaf margins for new growth and young leaves. (Well, IIRC.) There are no signals I remember for having too much K in the mix. But.. as always.. this may or may not apply and may only extend to the seagrasses.

A general reference on nutrients in land plants, possibly helpful.

I think for small tanks the case is a bit moot given you will be exchanging pretty steady amounts of water each week. For larger systems - like the one you are planning - it might be much more helpful to see what is going on and to judge water changes from that data directly. Or to adjust dosing K to the system appropriately.

The only test kit I think we were able to find for potassium was from LaMotte, though Habib would of course be a great person to speak with on this point in specific.

>Sarah

 

[Samala]

On the other hand, if I just did the math correctly, each time I dose KNO3 into the tank to raise it 5ppm each day of the week I'm enriching the K levels by 3.15ppm, or ~21ppm each week. Without any uptake/precipitation that means K went from 385 naturally to say 406ppm. With water change, back to possibly 395ppm. You can see, easily, how over time this might start to effect the actual K levels without a major water change, or 'reset'.

>Sarah

 

[DaMan]

I use CaNO3 instead, know that my corals will uptake the Ca+. I hope that K+ is replenished through my salt additions. I would like to see evidence of K+ interaction in our tanks, also. In humans, hyperkalemia is deadly. In fact, it is used in lethal injections to stop the heartbeat. I am nervous to expose my fish to higher than normal levels of K+.

 

[graveyardworm]

30 views 2 replys and not a single vote for the poll?

 

[Samala]

David I think its a good project for someone to take on... (hint hint)

Honestly maybe this is something several of us can look at, perhaps a few people with only macroalgae, a few with seagrasses, and some mixed tanks going on? I guess I cant just live in oblivion land hoping that things are going well. Time to look into that LaMotte kit I suppose.

Man I should submit a grant for all these 'grass experiments.

>Sarah

 

[graveyardworm]

I have a pile of 10 gallon tanks, most I've acquired at the dump. So as soon as I can free up a little more space in my basement I would like to set up some species specific tanks and see what makes them tick, and I think one area that is lacking is how K affects different macros. I've discontinued dosing in my lagoon setup because I've got cyano popping up on my LR, and some sort of mix algae on the sand bed. No microscope yet, but it looks like cyano/ dinoflagelates/diatoms. So far the only tanks its in are my refuge and mangrove. I'm thinking its the lighting cause those are the only tanks lit with 6500k, every other tank is 10000k and up.

Anyway getting back to the subject, I was maintaining 5 ppm NO3 with the KNO3 stump remover, and I would really like to know what the potassium #'s look like after the dosing. You say Lamotte makes a kit, any idea where they can be purchased?

 

[billsreef]

<a href=showthread.php?s=&postid=7239898#post7239898 target=_blank>Originally posted</a> by Samala
Man I should submit a grant for all these 'grass experiments.

>Sarah

You should My understanding is that the various folk invovled with trying to grow various seagrasses (most notably Thallasia and Zostrea) for use in ecosystem recovery have a fair amount of difficulty and could probably use the help.

 

[graveyardworm]

I'm still having trouble understanding something, the level of K in NSW is almost equivalent to the level of CA yet CA seems to get all of the attention. It would seem that K is a major player in the lives of our aquarium critters, inverts, and plants/macros yet very little research has been done to determine what its role is? I am very disappointed I wouldve thought science was smarter than that. In my searching I did find that someone has figured out that its important as it is part of the zeovit dosing system, so maybe they're onto something, either that or on something.

 

[DaMan]

Ca/HCO3 are depleted quickly in our captive systems by coralines and corals. The discovery of CA's and HCO3's importance in the acid/base balance is what has enabled our hobby to progress to systems that thrive seemingly indefinately.

There are many microelements that are in NSW. Strontium, boron, ect,ect. Have you seen research that implys that K+ is depleted and needs to be replaced ?

 

[Samala]

Right, there are so many constituents in saltwater that testing for every last little thing probably hasnt been deemed necessary. It was pretty obvious for corals that they were calcified and needed the element in their water, from there it must have been all nailed down with Ca/HCO3 and such. As for science, seagrass researchers do not typically worry about depletion of nutrients in the wild or in mesocosm experiments as they are either working within the ocean (and thing of the K reserves there!) or in flow through culture aquaria that is also buffered by the source water (typically.. again.. the ocean).

I do need to do some literature sources for potassium and seagrass and comb through my new 'grass biology books. Perhaps something will pop up in there.

>Sarah

 

[graveyardworm]

<a href=showthread.php?s=&postid=7243358#post7243358 target=_blank>Originally posted</a> by DaMan

There are many microelements that are in NSW. Strontium, boron, ect,ect. Have you seen research that implys that K+ is depleted and needs to be replaced ?

I havent been able to find any info or research regarding either the importance or unimportance of K to marine organisms, perhaps it has absolutely nothing to with the health of anything in the ocean and it doesnt matter if there is none of it or tons of it. Just wish I knew or could find out.

 

[DaMan]

I think it does matter if there is tons of it. It would be nice to know if it is consumed so we can just use KNO3, so I voted yes in your poll. But, I am too afraid of hyper levels of K+ to use it, so I have to use the harder to find CaNO3. But, if your system does not consume the CA+, that would be detrimental too. It would be nice to have a reliable test kit.

 

[Shoestring Reefer]

<a href=showthread.php?s=&postid=7234188#post7234188 target=_blank>Originally posted</a> by Samala
If you look at Randy's What is Seawater? RK articleIn freshwater aquatics, K deficiency shows up as yellowing of the leaf margins for new growth and young leaves. (Well, IIRC.) There are no signals I remember for having too much K in the mix.

Yup.

 

[graveyardworm]

I'm confused did you manipulate the quote? Is this found in Randy's article?

In freshwater aquatics, K deficiency shows up as yellowing of the leaf margins for new growth and young leaves. (Well, IIRC.) There are no signals I remember for having too much K in the mix.

or is this a quote from Sarah. Anyway it pertains to freshwater aquatics, and may have little or no correlation to marine plants.

 

[Samala]

Right, I mentioned as much, that it may or may not be true for marine plants. It may be worthwhile to note that I have never seen a deficiency for nutrients other than N though (as red new leaf growth) that are not foreshadowed by nuisance algae blooms. For instance, I have never seen yellowed new growth out of plants, or leaf margins, or other signals such as holes in leaves that are found among freshwater plants.

>Sarah

 

[billsreef]

I'd fully expect SW plants to need K just as much as FW, especially the vascular plants like sea grasses. Likely the biggest reason there has never been much research on the subject is the abundance of K in NSW. However, as we all know there can be quite a variation from needs to be done in a flow through system with abundant NSW and our little closed systems. Much of the current knowledge for keeping corals in closed systems comes from the hobby. I expect we will do the same for plants in closed systems

Although K is not needed for growth of phytoplankton.

 

[Samala]

Although K is not needed for growth of phytoplankton.

Or.. is it just that there is enough K available in NSW for phytoplankton to grow? I know what you mean though, there's no K in Guillard's formula.. but they are expecting you to grow up the phyto in ASW + F2. Experimental cultures of phyto are fairly rapid turnover situations: start a flask, grow to max pop level in a few days, harvest. Then again.. there are those pesky algae plates that are not very quickly refreshed. Hmmmm. Either way, phyto's must not use much of it. I would expect that the macro's dont either.

But, like you, I harbor potassium-friendly thoughts for seagrasses. Particularly since seeing a paper on K transporters from Cymodocea (see here). That single paper is about all I can find at the moment without going through several hundred back issues of Aquatic Botany or others. Someday I will get to it, I swear I will.

>Sarah

 

[DaMan]

Do you experts have any concern about the effects of too much potassium on a captive system?

 

[billsreef]

<a href=showthread.php?s=&postid=7256922#post7256922 target=_blank>Originally posted</a> by Samala
Or.. is it just that there is enough K available in NSW for phytoplankton to grow? I know what you mean though, there's no K in Guillard's formula.. but they are expecting you to grow up the phyto in ASW + F2. Experimental cultures of phyto are fairly rapid turnover situations: start a flask, grow to max pop level in a few days, harvest.

I'm kicking myself now :eek2: Can't believe I didn't think of the K in the SW used for the culture or the replenishment via the rapid turnover Considering the abundance of K in SW and ASW mixes, adding it the Guillard's would be like adding extra Ca.

I'll have to try and remember to take a look at that paper you linked tonight. Got to head to work soon.