The Refractometer is a must have for all aquarium hobbyists. The proper salinity is crucial for the survival and health of your fish and corals . This high quality refractometer is extremely accurate and easy to use and calibr...
The Captive Purity Refractometer is an incredibly accurate and easy to use device that eliminates the confusion associated with inexpensive hydrometers. Just place a couple of drops of water on the prism and hold to the light. Rea...