Hey, so I broke my old hydrometer and it was a very old hammy down hydrometer. So I decided to buy a refractometer to get better results. Now, I got it and I put RO water on it and it tested at the 1.000 that it says it should, and then I put my tank water on it and it tested at 1.020 which didn't seem right. So instead of dumping a bunch of salt I went to my local Petco and got a hydrometer and tried that it has a range of 1.014-1.028, and the hammer in it is going to the surface of the water reading higher than 1.028. So, which one do I trust? Is the hydrometer I bought compatible with saltwater? From what I read they are all the same. I'm gonna post links to both the hydrometer and refractometer.