I started testing my water a few weeks ago using Aquarium Systems SeaTest hydrometer. I dropped an broke one of the pivot pins on the pointer the other day and had to replace it. Only hydrometer my LFS
had in stock was Coralife's Deep Six. Specific gravity readings with the SeaTest hydrometer were 1.021-1.022. Now with the Deep Six hydrometer readings are 1.018-1.019 after doing as suggested my the manufacturer and letting the pointer stand in water for 24 hours to cure. I plan on purchasing a refractometer as my inhabitants require more precise measurements but until then I'd like to know what some of the other members here use and why they prefer the product.