Piper April 10, 2013 Share April 10, 2013 Never seen this before. I keep a constant 1.025 in the tank, adjust constantly. I go to do a 10% water change and test both the tank and new water and both show way below where they should. What can make a relatively new refractometer start to misread? Link to comment Share on other sites More sharing options...
Sharkey18 April 10, 2013 Share April 10, 2013 You need to regularly calibrate your refractometer. You can buy test solutions and then calibrate to that, or you can calibrate to a sample of RO/DI. The test solution is the best, but fresh water will do in a pinch. Hydrometers on the other hand give a very gross measurement. Link to comment Share on other sites More sharing options...
smallreef April 10, 2013 Share April 10, 2013 I recalibrate my refract about once every 2 weeks ... use the calibration solution...trying to do it with rodi water can cause low readings ive seen in mine atleast... Link to comment Share on other sites More sharing options...
Piper April 10, 2013 Author Share April 10, 2013 (edited) You know, the one thing I don't like about this hobby is how not a darned thing works as advertised for more than weeks or months without needing to be serviced. Hopefully business will boom and I can just get regular service to not do it anymore. Anyone got a link on how to calibrate a refractometer? Sorry to be negative. Just a PITA and it scares me. If it hadn't been an abrupt change in accuracy, I might not have noticed until my parameters were off enough to cause damage. Edited April 10, 2013 by Piper Link to comment Share on other sites More sharing options...
smallreef April 10, 2013 Share April 10, 2013 Its easy...the calibration fluid I have is 1.035 I think...so there is a tiny screw on top you put the fluid on the slide like normal and then turn the screw till it matches the number is it supposed to be:) Link to comment Share on other sites More sharing options...
smallreef April 10, 2013 Share April 10, 2013 You going to the meeting? I can bring my fluid and witty bitty screwdriver Link to comment Share on other sites More sharing options...
Cliff Puckstable April 10, 2013 Share April 10, 2013 I got my refractometer from brs over a year ago, and never had to adjust it. I check it was cali solution every so often. It's always spot on. Link to comment Share on other sites More sharing options...
Piper April 10, 2013 Author Share April 10, 2013 You going to the meeting? I can bring my fluid and witty bitty screwdriver Thanks. Is the meeting this weekend? I'm completely booked Saturday with a car show. Link to comment Share on other sites More sharing options...
Piper April 10, 2013 Author Share April 10, 2013 I got my refractometer from brs over a year ago, and never had to adjust it. I check it was cali solution every so often. It's always spot on. That's the weird thing. I've never had one go out like this either. They always seem to need replacing from abuse and neglect before I'd ever notice an anomaly. And this one went from spot on, presumably, to off by a whopping .005, reading 1.020 instead of 1.025. It's relatively new, out of reach of the kids, and kept in it's case. WTH. Link to comment Share on other sites More sharing options...
Sharkey18 April 10, 2013 Share April 10, 2013 Really? I calibrate mine all the time. For me it's really just part of using it. Link to comment Share on other sites More sharing options...
John April 10, 2013 Share April 10, 2013 I check it every time I use it...it stays true for months, but every once in awhile it needs to be adjusted. Swing by F&F, they will probably calibrate it for you...they also sell calibration fluid... Link to comment Share on other sites More sharing options...
mling April 10, 2013 Share April 10, 2013 I only calibrate mine with RODI water. Why would RODI not be 0.000 ? Link to comment Share on other sites More sharing options...
Huly April 10, 2013 Share April 10, 2013 Mine is on the fritz too it could be the type as Origami is taking mine to figure it out. Sean at F&F will help calibrate it as he had to help with mine multiple times before it went crazy. He will also test your water to see how accurate your Refractometer is compared to the store one. Link to comment Share on other sites More sharing options...
Integral9 April 10, 2013 Share April 10, 2013 Refractometers are sensitive devices. The mirror (I'm assuming) is set on a spring with a screw to change it's angle. Dropping it, bumping it hard or just even shaking it can cause the mirror to move around and thus loose it's calibration. Keep your refractometer in it's foam box and don't drop it, shake it, or even give it a stink eye, and it should last a long time. Hydrometers are error prone due to micro bubbles sticking to the arm. In addition they require regular use to be consistent and accurate. I think hydrometers are good for people who test their tanks every day or are in the service business as they test several tanks a day with it. Keeping them wet and letting a bio film build up is key. But if you are like me, and I think most people are in this case, and don't test your SG very often and mainly use it to test your water change water, the refractometer is what you need. Just need to be careful with them or they will fall out of calibration. fwiw: My refractometer has seen more than a few years of work, been dropped, banged, shakin, etc and should probably be replaced. The paint is peeling off and the aluminum housing is oxidizing. When I look into it, it produces a blue area, and then a thin blue line. The thin blue line is the correct reading I've discovered after comparing it's results to what Johnny's digital hydrometer read out at BRK. I think the mirror is cracked or something, but since I know where to look, I just go with it. Link to comment Share on other sites More sharing options...
Brian Ward April 10, 2013 Share April 10, 2013 I only calibrate mine with RODI water. Why would RODI not be 0.000 ? RODI is 0.00 and you can calibrate to this. The problem is that sometimes they will read correctly at 0.000 but adjust at an incorrect rate as salt is introduced. So at 0.000 they're right. At 0.01 they're close but maybe off by .005 and at 0.03 they're off by a full .01. This is why you ideally want to calibrate with solution at or near the value you want to test. Same logic applies for why you calibrate your pH probes at 7 & 10 to read tank water and at 4 & 7 to read a Ca Reactor. Need to calibrate around the values you want to read to ensure maximum accuracy. Link to comment Share on other sites More sharing options...
STEVE April 10, 2013 Share April 10, 2013 Bring it by...I will calibrate it for you Paul, I have both 0 and .35 calibration solution. Link to comment Share on other sites More sharing options...
Piper April 10, 2013 Author Share April 10, 2013 I hear ya, buddy, and I really appreciate it. But Manassas is a LONG way for me. Link to comment Share on other sites More sharing options...
STEVE April 10, 2013 Share April 10, 2013 I hear ya, buddy, and I really appreciate it. But Manassas is a LONG way for me. . LOL you live in Manassas and so do I....LOL :clap: Link to comment Share on other sites More sharing options...
Origami April 10, 2013 Share April 10, 2013 . LOL you live in Manassas and so do I....LOL :clap: Steve, Piper lives up my way... Piper27 (Paul) is down in Manassas. Link to comment Share on other sites More sharing options...
STEVE April 10, 2013 Share April 10, 2013 (edited) :bb: Sorry!!!! I guess I should have looked closer, my apologies!! Edited April 10, 2013 by STEVE Link to comment Share on other sites More sharing options...
Origami April 10, 2013 Share April 10, 2013 (I admit, I have to look twice at the names sometimes!) Link to comment Share on other sites More sharing options...
smallreef April 10, 2013 Share April 10, 2013 Meeting is Sunday, not Saturday this time Link to comment Share on other sites More sharing options...
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