How often do you calibrate your refractormeter??

[Reef Pilot]

To satisfy my own curiosity, I just tested my Sybon again. It was dead on with both the 0 ppt and 35 ppt calibration solutions. I went out and bought the 35 ppt solution the last time we had this fear mongering on the forum.

I have owned it now for over 4 years (use it before and after water changes) and have never had to calibrate it.

[lastlight]

maybe it's the bumping some people do? I handle mine like fine china just out of habit. I plan to test to satisfy my curiosity but I will be shocked if it's not still accurate.

[The Guy]

I have a Sybon and every time I've checked it it's always bang on. Had it 2 years now and have only checked it maybe 4 times.

[randallino]

Originally Posted by lastlight

maybe it's the bumping some people do? I handle mine like fine china just out of habit. I plan to test to satisfy my curiosity but I will be shocked if it's not still accurate.

I agree.
I've got a Sybon and as long as I'm gentle handling the refractometer its fine. I do check calibration about ~3 months.

[SeaHorse_Fanatic]

My Sybon has also remained very accurate. The Vertex refractometers, on the other hand, seem to be a lot more finicky.

[jhj0112]

I also have Sybon and I handle it with really good care.. I am still going to check though...

[mike31154]

I like to think I'm relatively careful with mine, with regard to the bumping & handling biness. It still goes off cal a point or 2 from time to time but I don't sweat it that much. I generally use it when doing water changes to compare the tank water to the new water simply to confirm that the difference is not too much. Water changes are large in my case, about every 21 days so I'm not too keen on shocking the livestock by dumping a bunch of new water with significantly different salinity on them. So, regardless of whether the reading is off (I shoot for 1.025), provided the tank & new water are within 1 point, I go for it.

IMO, it's easy to over think these things. I mean once you have your tank salinity set to the desired value & your top off system is working properly, there really isn't anything other than a water change that will tend to change it. This is why I simply ensure the new water is close to the tank water before I do a change. If I feel ambitious, I'll put a drop of tap water on the refractometer & tweak the adjustment to make it read 0. Other than that, I see the tank virtually every day, so if something's amiss, I investigate. Usually it's not incorrect salinity. After years of running the tank & making up new water in the same container using the same salt, I have a pretty good handle on how many cups I need to mix to get close to 1.025. So should be no reason for the tank salinity to drift more than a point after a water change.

A few years ago I used the refractometer to compare tank water readings with 3 cheap swing arm hydrometers and a floating hydrometer. Salinity showed 1.025 on the refracto. The floater was bang on same as refracto, the swing arm jobs were all off by quite a few points. Rather than turf them in the trash, I put a mark on each of the cheapo swing arm hydrometers to show where 1.025 was according to the refracto. So theoretically I should be able to use the swing arms to confirm whether the refracto has drifted or not. Haven't done that in some time though, so I should probably trash them. Nevertheless, if anyone has a swing arm still kicking around & is concerned about their refracto drifting, they could do the same & use it as a backup. Better yet, invest in a floating hydrometer, they are very accurate, provided you use them at the design temperature, or compensate with a chart.

[wreck]

went out and bought some solution to check mine after reading this thread hadn't tested it in a year or better. it was dead nutz, vertex refractometer. i use it put it back in the case, never gets bumped.