Why would potassium be depleted in my tank?

[ScottB]

I don't often test or dose K. It never seemed to move much.

After a second round of fighting ostreopsis dinos, I tested for giggles and got a reading of 250. I tested twice. Salifert kit, expiration 2/20.

I dosed 50ml spread over a week and got back up to 300. Tested twice. So over the next couple weeks I will get back to ~400. Fine. Makes me wonder what else might be depleted. Guess I will send off an ICP.

BUT WHERE DID MY POTASSIUM GO?

Did the dinos consume it?

Other details:
260G SPS frag system
IORC salt at 8ish dkh
ESV 2 part
A couple dozen large tangs, wrasses, lawnmowers
Recently wound down NO3 and PO4 dosing

 

[Randy Holmes-Farley Verified Community Expert]

Getting a second measurement is good.

In general, potassium is held by organisms inside of cells. That includes foods. If you feed a food frequently that has broken cell membranes and is then washed (by you or the manufacturer), the potassium may be washed away.

A big way it can decline is by using a two part that does not include it, but ESV has it.

 

[ScottB]

As stated in my original post, I never cared much about K until on a whim I tested after dinoflagellates. Test was very low at 280 versus 400 NSW.

Sent off the ICP to Colorado on Thursday to confirm deficiency. In the meantime got another Salifert kit ( as my searches rendered no better test kits aside from Triton and ICP) and the new kit seems to confirm previous.

My display is a bit low at 370, but 260G frag system that had dinos is 280 level -- where it was even after maintenance dose of Brightwell K. This seems to suggest I am low in K there.

Until ICP comes back I will just keep maintenance dose going as no SPS seem to be noticing,

I use IORC salt and WC 20% every 2 weeks on DT; about 15% every 2 weeks on Frag system. Will look to increase frag system WC.

Anybody seeing this after a dinoflagellate episode? Where did all my potassium go?

Does potassium matter that much?

 

[ScottB]

Just to wrap this up, the second ICP came back low, but higher than the first ~300. I kept dosing until Salifert reported 400 and stopped dosing altogether. That is now almost a year without subsequent dosing and my latest Triton ICP read 430 which is middle of their suggested range.

I can figure two possible scenarios that lead to low potassium back then (as my livestock and feeding is largely the same).

a) The Ostreopsis dinoflagellates consumed K.
b) My salt batches over a long period did not contain potassium

Or maybe something else.

 

[PR_nano]

Following, I did my first ATI ICP recently and also had really low Potassium.

Potassium

187.4 mg/l

391.2 mg/l

-203.8 mg/l

How much Potassium are you dosing daily? Trying to figure out if it should be brought up slowly over time. Interesting scenarios I will test my next batch of freshly made salt to see what it's mixing at. I'm also battling some dinoflagellates.

 

[blasterman]

Potassium should be a component of your main salt. I believe it has the same rough composition percentage as calcium.

However, since reef salt makers have no official agreement on what they put in salt you might find it varies - a lot. Some consider it a major trace element (???) This is why I get short tempered when we fling terms like trace elements because there is no standard, and for things like potassium there should be.

I would first check your salt mix.

 

[Randy Holmes-Farley Verified Community Expert]

Just to wrap this up, the second ICP came back low, but higher than the first ~300. I kept dosing until Salifert reported 400 and stopped dosing altogether. That is now almost a year without subsequent dosing and my latest Triton ICP read 430 which is middle of their suggested range.

I can figure two possible scenarios that lead to low potassium back then (as my livestock and feeding is largely the same).

a) The Ostreopsis dinoflagellates consumed K.
b) My salt batches over a long period did not contain potassium

Or maybe something else.

All growing organisms consume potassium, and all foods add it.

The question for depletion or accumulation is which tissue is holding more: the potassium in tissues created in the tank, or the potassium inside of tissues fed to the tank.

Also, if you use a DITY two part that does not include potassium, that process will deplete it substantially over time. CaCO3/C2 reactors and limewater/kalkwasser will not have that eeffect.

 

[Randy Holmes-Farley Verified Community Expert]

Following, I did my first ATI ICP recently and also had really low Potassium.

Potassium

187.4 mg/l

391.2 mg/l

-203.8 mg/l

How much Potassium are you dosing daily? Trying to figure out if it should be brought up slowly over time. Interesting scenarios I will test my next batch of freshly made salt to see what it's mixing at. I'm also battling some dinoflagellates.

I would bring it up over a week or so.

 

[ScottB]

All growing organisms consume potassium, and all foods add it.

The question for depletion or accumulation is which tissue is holding more: the potassium in tissues created in the tank, or the potassium inside of tissues fed to the tank.

Also, if you use a DITY two part that does not include potassium, that process will deplete it substantially over time. CaCO3/C2 reactors and limewater/kalkwasser will not have that eeffect.

I need to process further the timing of the few changes across the two systems (Frag vs Display). Only the frag system depleted (past tense) K.

Similarities: Livestock and food very similar. Bacterial rock & block the same although display older and with sand. Frag is larger 300G vs 139G.

Display has always been ESV 2part; no dinoflagellates; nominal K and low I.

Frag was ESV for first several years; got dinos; lost K and I. Dosed both for a while and in the same time switched to CaRx. Supplementing of K and I is no longer necessary.

A lot of moving parts there I know, but nothing jumps out about differing inputs/outputs aside from CaRx versus ESV which I never thought about before.

Thank you for the continued input @Randy Holmes-Farley it is appreciated.

 

[ScottB]

Potassium should be a component of your main salt. I believe it has the same rough composition percentage as calcium.

However, since reef salt makers have no official agreement on what they put in salt you might find it varies - a lot. Some consider it a major trace element (???) This is why I get short tempered when we fling terms like trace elements because there is no standard, and for things like potassium there should be.

I would first check your salt mix.

As that post was >1 year ago, I cannot check what K was like for my IORC. It is still one of my two suspicions but I cannot confirm it; the other culprit potentially being the ostreopsis as a consumer. The latter actor bears weight as I think of it because my display (sans ostreopsis) did not see a K drought using the same salt bags. I just don't know for sure though.

 

[Randy Holmes-Farley Verified Community Expert]

I've not personally seen any analysis of a salt mix that suggested it had low potassium.

 

[blasterman]

I've not seen consistent analysis of salt mixes in general that confirm if they have potassium at all. It's typically some guy that has time on his hands that does an analysis of the major brands. I'm sorry, but having worked in the chemical manufacturing industry I don't trust any salt mix when it comes to anything other than sodium chloride, calcium chloride, sodium bicarb and magnesium. Iodine is typically a contaminant of the salt purification process.

The only reason I trust those main ingredients is simply because reefers can test those, and if there were major screw ups we would hear about them.

 

[Randy Holmes-Farley Verified Community Expert]

This one from long ago was done by an expert chemist:

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