What would be a quality relativivly cheap refractometer. The 10$ hydrometer is not pulling it's weight anymore. Especially with adding more and more coral's. I would rather pay a little more and have that peace of mind than guess with the hydrometer. And also a good RO/Di unit im looking into. If anyone can nudge me in a good direction I would real be thankful. ![Big grin :D :D](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)