Bad Salifert Potassium test kit

[jjencek]

I have been having problems with most of my SPS specially the acros were just not happy. I kept testing all my values and all were stable. I have been dosing several things including potassium. Of course I listened to the forum and don't dose anything I don't test.

I recently was running out of my Salifert Potassium kit. I bought a new one. What a shock! My new test kit measured over the scale of 470 ppm while the old one was at 380 ppm.

I did four 25% water changes and I am now at 440 ppm. My old test kit expiring in June 2019 is showing 320 ppm.

My corals like the milka are getting happier. The acros are still bad.

 

[bertoni]

How old was the old kit? They do tend to read lower over time as water evaporates from the reagents.

 

[jjencek]

About one year

 

[bertoni]

Hmm, that's a bit disappointing. How often were you measuring the level?

 

[jjencek]

I was testing every 1-2 weeks. Looking at my notes things were starting to go bad about 6 weeks ago. I have been trying to figure out why since then. I sort of got lucky by running out of the test kit and buying a new one.

I am changing a few things based on this experience ...

1. Watch for unusual swings out of norm.

2. Usage of elements should be in ratio. So more calcium, should correspond to more of other stuff.

3. Test my test kits by measuring my fresh batch of salt water. I am using RedSea.

4. I am switching dosing of elements to RedSea program where the minor elements are somewhat tied to Calcium consumption.

Anybody has other/better suggestions?

 

[bertoni]

I don't have much to add. Keeping the reagents capped as much as possible should help a bit, but that's all I have.