Här är de hydrometrar man testade om någon är intresserad: Hydrometer - by Marine Enterprises, Inc. Deep Six - by Coralife SeaTesT Full Range Specific Gravity Meter - by Aquarium Systems The first hydrometer by Marine Enterprises tested a sample of seawater at 1.023. Perfect to many hobbiests, a little low to others The second hydrometer by Coralife measured the same sample source of seawatr at 1.030! Almost a certain death for most organisms in captivity if maintained for a short length of time! And last but not least, the SeaTest by Aquarium systems. This hydrometer measured the same source water at 1.028, close to the same reading as the previous water.<BR clear=all>