refractometer troubles....

i have been having issues with my refractometer. originally, i had one of the ebay ones i think it was around 30 bucks or so. After only a few uses, the rubber grip fell off of it. The problem i was having with it was i would get drastically different readings from it even from the same water source. i was also letting it temperature adjust so that wasnt the issue. I calibrated it with ro/di.....but just didnt trust the constantly changing readings. I ended up ordering a new one from premium aquatics for 50.00. this one included 35ppt calibration fluid. When trying to calibrate, i could not turn the screw enough to get it to the 35ppt mark on the scale....the screw would just turn and keep unthreading from the unit. The most i can get the scale to go up to with the fluid is 1.025, which i know is ideal anyway. should i just use the fluid to calibrate to 1.025 and be comfortable there? i noticed 35ppt is a few notches above 1.025 on the scale. I just want to feel at ease that i am getting a good measurement!

 

Yes. It's close enough. The calibration fluid is key!

You still may want to try and return it if possible.
It is a precision tool and you should be able to adjust it to the correct reading.
What a PITA.

 

I had a similar issue on mine. I really had to crank down on the screw to get it to read 35ppt.

But as mentioned, as long as you calibrate to the same every time and keep your salinity in the tank consistent (even if it is actually 1.025 but reading 1.024), you should be all set.

 

should i just accept it and calibrate it to the 1.025 with the solution? or try to get a replacement? im just so tired of dealing with this.

 

I would get a replacement.
I think the reason you could not get consistent results with the first one you had is the rubber grip is there to keep your hand from heating up the refractometer.Believe it or not your body heat will cause the temp of the metal to change drastically.