This top light is -- I'm sorry if I'm making you seasick -- this top light is actually a water quality display that shifts from red, when the dissolved oxygen is low, to a blue/green, when its dissolved oxygen is high.
Gornje svijetlo -- isprike ako imate morsku bolest -- gornje svjetlo je zapravo pokazatelj kvalitete vode koje se mijenja iz crvene, kada nema kisika, do plave, zelene, kada ga ima.