Bubblefin ATC Salinity Refractometer - Dual Scale (1.0 to 1.070 S.G.)

Pretty easy to calibrate and use. Instructions and you tube videos helped. Great value for a small price.

I had my local marine fish store calibrate it for me and since then it works really well. It is easy to read and seems accurate.

I used to use the old style refractors where you fill the water and the level balances out but these are way easier to use and accurate enough just do not drop it because if you do it will break and you will have to order a new one

This is an absolute must-have for saltwater aquarium owners. As a new hobbyist, I didn't know how often I'd be checking salinity so I was looking at those plastic readers. But now I'm realizing that I check it CONSTANTLY. From the display tank, to the fish I just bought, to the coral I just bought, to the saltwater I just mixed, to the quarantine tank I need to water change, etc. I check salinity CONSTANTLY. I'm at the point where I'm probably going to buy a second one of these so I have one in each room. Calibration was quick and easy. I've already learned how different the local fish stores keep their water versus even the saltwater they sell.I have no complaints with this item at all...if anything my complaint would be that the eyedropper that is included to pick up your water sample, holds a TON of water and you only need a couple drops at a time. That's not really a complaint, more of a heads up to new users just learning how to do this.Great product.

Works well, my only complaint would be that it is somewhat difficult to read. Make sure that you have excellent overhead lighting when you are reading and you should be okay.