Potassium test kit numbers

spspirate · Mar 18, 2017

Hey guys. I'm looking for a potassium test kit that will measure much higher than 470ppm. I have the salifert and that's where it tops out at. Which one reads well beyond that? Thanks

just playing around with my potassium levels to see if there's any deeper/richer pigment change with a few of my corals.

spspirate · Mar 19, 2017

TUSI · Mar 19, 2017

tought salifert reads higher but anyway higher will kill everything

spspirate · Mar 20, 2017

I don't see raising it slow and steady would be detrimental to SPS. In fact several people have raised it 2x's and even heard of one person raising it 4x's NSW. Justin Credable briefly talks about it during MACNA 2014. My levels at the moment are beyond what Salifert reads and corals look fine.

TUSI · Mar 20, 2017

spspirate said:
I don't see raising it slow and steady would be detrimental to SPS. In fact several people have raised it 2x's and even heard of one person raising it 4x's NSW. Justin Credable briefly talks about it during MACNA 2014. My levels at the moment are beyond what Salifert reads and corals look fine.

Good to know. if you dont mind sending me any link that talk about this i would really appriciated cause i was always under the impression that to high potasium is detrimental to corals.

Randy Holmes-Farley · Mar 21, 2017

I'm not familiar with the upper end of any of the available potassium kits.

Are you intentionally trying to raise it higher, and if so, why?

spspirate · Mar 21, 2017

Yes I would like to run my potassium at around 800 ppm for a while to see if there is a positive difference as stated above. I've heard of people doing this and the claims of great colors but do not have a test kit that will read anything that high............that's where I'm looking for input.

Randy Holmes-Farley · Mar 21, 2017

spspirate said:
Yes I would like to run my potassium at around 800 ppm for a while to see if there is a positive difference as stated above. I've heard of people doing this and the claims of great colors but do not have a test kit that will read anything that high............that's where I'm looking for input.

Assuming you start with normal levels, you can readily determine how much to dose to hit that level. That might just as accurate as using a kit. More accurate if you know your total volume well.

FWIW, I have heard of folks with problems and none with advantages of overdosing potassium, but those aren't controlled studies.

sundog101 · Mar 21, 2017

I have the salifert which goes up to 470 and I haven't found one that goes much higher. I'd like to keep mine in the 500 range.

Randy, would diluting the test water by half with rodi give half the result? So 500 diluted would be 250?

I've also heard Justin mention something about "retitrating"

spspirate · Mar 21, 2017

Good point

Randy Holmes-Farley · Mar 21, 2017

I'm not sure how important the salinity is for a potassium test accuracy. You can test that by taking some tank water, getting a result, and adding RO/DI to the tank water to see how the value drops, and if it drops by the dilution amount expected.

sundog101 · Mar 21, 2017

Alright, I just tested it. My potassium right now reads 400ppm (10 drops). I added 0.5ml of tank water and 0.5ml of ro/di water. It took 30 drops which would be 200ppm. The test shows the reading down to 250, but if 1 drop equals -10ppm, the result would be 200. So it seems to be right; keep in mind I only did a couple of tests through.

Randy Holmes-Farley · Mar 22, 2017

I didn't follow what you said, but if the test on the same total volume of water (which is half tank water and half RO/DI) gave half the potassium level, then you are good to go with dilution.

sundog101 · Mar 22, 2017

Randy Holmes-Farley said:
the same total volume of water (which is half tank water and half RO/DI) gave half the potassium level

Yes that's a better way to word it

michaelfaulk · Apr 29, 2017

Any point of sale/neg seen yet from raising K?

sundog101 · Apr 29, 2017

I've had K at around 420 (not really high) for a couple months now. No negative results. I can't say that I can really tell a difference in anything though.