I have one of the Calcium probes and meters, but I use them intermittanty, rather than continuously, as after about 2 weeks they drift so much from the Salifert responses that I find it necessary to recaibrate the meter. As the probe needs to be stored in the calcium solution for the period it is out of the tank, I almost find it more difficult to do what is necessary to keep the probe in good shape as it is to do the Salifert titrations.
AInterestingly enough, placing the probe in an area of good turebulance affects the response of the probe, sometimes by as much ays 60 to 80 PPM. When removed from areas of heavy current flow and placed in calm waters, the test results come much closer to
Salifert test responses than when in the high current areas. Not sure why, I should prolly post a question to Randy to see if he has any experience with this.
I would think temperature in aquaria might be an issue, but at 80 to 82 degrees F, the tests are very close to the Salifert results.
I originally bought this device thinking I could leave it in the display tank with the ultimate intention to use one in each tank the same way I use the pH probes, but that just hasn't worked out with the issues of wander from calibration. However, I have found that I can walk from tank to tank and test, such that placing the probe in the tank and waiting for 4 or 5 minutes allows the probe to come to a steady value that is usually within 10 to 20 PPM if not dead on of what I have testing with the Saliferts, so rather than do 6 Salifert tests (including the effluent from the calcium reactors), I can just test, rinse, test, rinse, etc. until I am done (I you intend to test tanks and effluent, test the tanks first, then the effluents, it takes a bit more time to stabilize the readings when there are relatively big jumps in calcium concentration, but this may be due to the high concentration of alkalinity or pH shift instead, I dunno). I have on occasion had the value stabilize in less than 2 minutes between similar test samples, such that I can finish testing in less than 20 minutes, rather than taking close to 40 minutes otherwise. I would NOT throw away the Saliferts, as I am still testing the water each time with the Salifert in the display tank, but all the other tanks get the probe only so long as the probe stays close to the initial Salifert test value for each session.
As far as would I buy one again? I am not sure, I am concerned about the cost of the probe replacement being almost as much as the probe and meter, a nice toy, and if you have multple samples to test, definitely a timesaver, but not sure that it is worth the money at its current price.
HTH
