Nature at Home – Home for Fish and Plants
Lesser animals and corals need to feel as much at home in the aquarium as they do in the wild. In a marine water aquarium, this includes the right water values, the right light, a varied and species-appropriate diet and of course the right salinity.
Density in marine water aquariums
When aquarium water evaporates, salts remain and they increase the density in the aquarium. To prevent damage to fish and invertebrates it is important to check the density regularly and to take any appropriate steps.
Density is temperature dependent:
At 25 °C, hydrometers indicate exactly the right density. Higher temperatures will require a correction factor, which is indicated in the JBL hydrometer on a scale next to the built-in thermometer. At 30 °C, for example, 0.001 needs to be added to the indicated density of, say, 1.022. The correct density at 30 °C would therefore be 1.023. At water temperatures below 25 °C a correction factor would have to be subtracted, e.g. at 20 °C 0.001 would have to be subtracted from the displayed density value. So if this is 1.025, the real density at 20 °C is 1.025 minus 0.001 = 1.024. If the water temperature in cold marine water aquariums is 15 °C, a correction of -2.5 ° needs to be made.