Vertex Refractometer

intarsiabox · #1 06-06-2009, 01:24 PM

I can get this refractometer from JL Aquatics for $50. Has anyone tried it? Is it accurate? Other places I've looked all sell their refractometers for about $80 and I am just wondering if their is a difference. Thanks!

alamo · #2 06-06-2009, 04:46 PM

For saltwater purpose it is more than enough. Make sure it is calibrated properly.

intarsiabox · #3 06-06-2009, 05:06 PM

Thanks for the input! I think I will go ahead and order it.

PuffLuv · #4 06-06-2009, 05:41 PM

I just bought one this week. I used distilled water to calibrate it, leaving it on the lens for about a minute to adjust to the correct temperature. It was out of calibration by a couple points when I received it, so I turned the screw slightly with the supplied screwdriver and it is now accurate. J&L had another refractometer for almost $10 more, but the only thing really different is that it came with its own "pure" water. Supposedly, "they look like they come from the same plant".

BlueAbyss · #5 06-06-2009, 08:28 PM

Mine was almost dead on when I got it. Excellent instrument, and a decent price.

Fijian · #6 06-12-2009, 02:15 AM

I just received mine and it works great. Jl delivers quick!

icecool217 · #7 06-12-2009, 10:37 PM

same here. mine was like 0.0005 off. adjusted it and now it works perfectly! great unit

intarsiabox · #8 06-13-2009, 12:02 AM

Thanks for everyone's feedback on this unit. It sounds like it works well and is a bargain at the price!

Cheers

BlueAbyss · #9 06-13-2009, 08:52 AM

Hmm, how did you calibrate it ice? Just using distilled, and then letting it adjust to the temp and then adjusting the unit?

Stones · #10 06-13-2009, 12:37 PM

To properly calibrate a refractometer used to measure salinity, you will get a much more accurate reading if you use the Pinpoint Salinity Calibration Solution instead of distilled water. Although it doesn't say it on the bottle, the Pinpoint salinity calibration solution is exactly 35 ppt.

When I first got my refractometer I used distilled water to calibrate it as well. After taking a reading from my tank it showed the salinity was 1.025. Two years later I purchased a bottle of the pinpoint calibration solution on advice from someone on RC. After re-calibrating the refractometer using the pinpoint solution, I checked my tank to see if the reading changed. To my surprise, the tank read 1.021. I never knew it but for close to 2 years I had been keeping my tank at only 1.021! The livestock didn't appear stressed ever but I noticed much better polyp extension and faster growth rates in my corals once I had brought my salinity back up to 1.025.

With all the things that can negatively impact the livestock in our tanks, keeping the salinity at near natural sea water levels is often overlooked. For the $5 it costs to get the calibration solution, its well worth it in my books.