My KH Director is showing a reading of 8.0 DKH. My Hanna checker shows 8.8 DKH and Salifert at 8.6. That's a pretty wide range. I have recently calibrated the probe in the KH Director so that shouldn't be the reason.
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That's the problem. I know we're looking for trends as much as anything but a 10% difference in readings is pretty significant.Apparently the Neptune Apex guys are experiencing the same thing with their Hanna Alk checkers, getting anywhere between 0.7 to 1 dkh higher results than what their Tridents are reading for Alk. As far as the Salifert results go, I haven’t seen any comparisons as yet. The question is, which one are we to trust as being accurate?
That's the problem. I know we're looking for trends as much as anything but a 10% difference in readings is pretty significant.
I just went through an alkalinity spike that killed a couple of my colonies and damaged a few more. I'm just trying to determine where my alkalinity really is and try to use the KH director to stabilize it.Indeed that is quite a discrepancy. However, if your corals are doing fine and are healthy, I would be hesitant to make any changes to your Alk level.
I just went through an alkalinity spike that killed a couple of my colonies and damaged a few more. I'm just trying to determine where my alkalinity really is and try to use the KH director to stabilize it.
Where was your PH level when your alk spiked?I just went through an alkalinity spike that killed a couple of my colonies and damaged a few more. I'm just trying to determine where my alkalinity really is and try to use the KH director to stabilize it.
My PH varies from about 7.85 at night to a little over 8 during the day.Where was your PH level when your alk spiked?
I was just curious because I read recently high 8.3+ PH can cause the ALK spikes so I was curious if that happened to you.My PH varies from about 7.85 at night to a little over 8 during the day.
I was just curious because I read recently high 8.3+ PH can cause the ALK spikes so I was curious if that happened to you.
Thank you, I got that mixed up.High pH will cause an alk DROP, not spike. Absorption is increased with higher pH, its what many people do to increase coral growth.
I’m having the same issue with my KH Director.GHL makes a 7.5 KH standard solution. I picked that up to make sure my testing was accurate. I have the same issue as you and my Director is not even close to accurate. I'm working with GHL through their online support system but so far I am very unimpressed. My Hannah, Salifert, Red Sea, and Tropic Marin KH test kits all come within reason of the 7.5 standard (+/- 2 to 3) But the Director reads 6.4.
What are you using to measure for calibration?Calibrate the reagent head at least again, and include the tenths of a ML in that. It does require a fine graduated cylinder, or a scale with low enough weight resolution. There is quite a big difference from rounding that figure up or down, or eyeballing it if there are no graduations between 4 and 5 ml. Something I found out and corrected, and now the kHD reads within .2 of the 7.5 reference solution with a 80ml sample being used.
As an aside, the Hanna alk reagent has a very finite shelf life. If it's been open for more than 2 months I wouldn't trust its accuracy completely.