Whitebeam
New member
Before I start, let me state that I am not associated with Salifert or any of its employees or agents other than as a satisfied customer of their products.
The new Salifert Potassium 'Reef Test' arrived in the post today. The box sports their new design for their new Reef Test range:
And contains the usual sort of things:
Ok - so far so good, but does it work? The only potassium reference solution I have is the FM multi reference. The FM bottle states that its K concentration is 408mg/l. Now my previous discussions with Habib have indicated that Salifert calibrate their tests to read ppm as mg/kg; as 1kg of S=35 water (including the reference) has a density of 1.025kg, this makes the K concentration of the reference 398.0mg/kg.
I have now conducted the test twice against this reference, with a clear result of 400ppm (mg/kg) each time. The test reads in steps of 10ppm, so I can state that, straight out of the box, this test gives a clear reading which appears to be accurate to within the tolerance of its resolution.
It is worth noting that the end-point colour is a very delicate baby-blue vs the cloudy white of the test sample prior to the end point. This was easy enough for me to spot against a white piece of paper in a room lit by bright indirect sunlight - I'm not certain if this will be quite so easy to spot in a room lit using the usual compact fluorescent household bulbs - I'll try this at some point in the future (once my test vials have finished soaking in citric acid for 12-24 hours to clean out the scale/scum that the test leaves in the vial (this cleaning step in either vinegar or citric acid is included in the instructions).
Summary: An accurate test within its resolution of 10ppm steps. The end point may be a little subtle for those who have difficulty seeing blues, but was very clear to my eyes.
Peter
The new Salifert Potassium 'Reef Test' arrived in the post today. The box sports their new design for their new Reef Test range:
And contains the usual sort of things:
Ok - so far so good, but does it work? The only potassium reference solution I have is the FM multi reference. The FM bottle states that its K concentration is 408mg/l. Now my previous discussions with Habib have indicated that Salifert calibrate their tests to read ppm as mg/kg; as 1kg of S=35 water (including the reference) has a density of 1.025kg, this makes the K concentration of the reference 398.0mg/kg.
I have now conducted the test twice against this reference, with a clear result of 400ppm (mg/kg) each time. The test reads in steps of 10ppm, so I can state that, straight out of the box, this test gives a clear reading which appears to be accurate to within the tolerance of its resolution.
It is worth noting that the end-point colour is a very delicate baby-blue vs the cloudy white of the test sample prior to the end point. This was easy enough for me to spot against a white piece of paper in a room lit by bright indirect sunlight - I'm not certain if this will be quite so easy to spot in a room lit using the usual compact fluorescent household bulbs - I'll try this at some point in the future (once my test vials have finished soaking in citric acid for 12-24 hours to clean out the scale/scum that the test leaves in the vial (this cleaning step in either vinegar or citric acid is included in the instructions).
Summary: An accurate test within its resolution of 10ppm steps. The end point may be a little subtle for those who have difficulty seeing blues, but was very clear to my eyes.
Peter
:K), this would translate to roughly 203:71:3.1:1.9 (C2H5OH:NO3
