Potassium test kits

[bigbuckdown]

What do we go by. My friend has the ELOS K test kit and i have the Red Sea test kit my kit reads potassium at 344 and the elos reads over 600. I have no idea what to go by. Anyone have expierence with these kits on which is more reliable?

 

[Randy Holmes-Farley]

Unless you are adding potassium, the Elos seems too high, and the Red Sea about right, but I've not seen tests on either of those two. I've only tested the Fauna kit and it tested my seawater standard reasonably well. The early review on the Salifert also says it is reasonably accurate.

What salt mix do you use? If it is a reasonable brand (like IO), you can probably make it to 35 ppt and test it with both kits and see which one comes closest to NSW values, which the salt mix probably has (roughly).

 

[bigbuckdown]

Im adding zeo k+ thomas pohls says to add equal amount of k+ when adding flatstop. I use reef crystals.. Would you happen to know what the k is when salinity is at 1.025?

 

[yeldarbj]

I've used both of those kits. I couldn't stand the Elos b/c of the turbidity reading. I found it very difficult to get a result. I drove myself crazy trying to decide whether or not I could see the black dot. At least with the Red Sea kit there is a clear end point. I have no idea how accurate it is, but I felt better about getting a definite result. Unless you've added a lot of K+, I would guess the Red Sea test is closer.

 

[Whitebeam]

I can certainly recommend the new Salifert kit. A clear colour change and apparently accurate to within its resolution to 10ppm.

http://www.reefcentral.com/forums/showthread.php?t=2169944

Peter

 

[Randy Holmes-Farley]

Im adding zeo k+ thomas pohls says to add equal amount of k+ when adding flatstop. I use reef crystals.. Would you happen to know what the k is when salinity is at 1.025?

To match NSW at that specific gravity, potassium would be about 378 ppm.

 

[bigbuckdown]

Im sorry i worded my question wrong. I meant to ask if you knew what the potassium level is with reef crystals when the specific gravity is 1.025. I tried googling it but couldnt find my answer

 

[Randy Holmes-Farley]

It isn't generally known, so you probably won't find it by googling. Potassium in RC should be about 398 ppm at sg = 1.025

 

[bigbuckdown]

Thanks Randy. I called IO and they gave me a number of 420 either way thats close enough to see which test kit is closest since the number im getting with elos and red sea are so far apart

 

[Randy Holmes-Farley]

That 420 is for 35 ppt, which is a sg of 1.0264. That's how I calculated the number I gave you for sg = 1.025.

 

[bigbuckdown]

tested

tested

tested the red sea kit and the elos using freshly made reef crystals. elos i got 500 and red sea i got 368. so im going to go with the results from the red sea test kit.

 

[Randy Holmes-Farley]

Sounds reasonable.