unless if the fishes have imaginary friends i cannot see no one is rubbing the glass.theplatypus;209748 wrote: It might be someone rubbing rubber on the glass.
LorenK;209788 wrote: Maybe one of the fans in the canopy going bad? Ballasts can make sounds as well.
tebriel;209851 wrote: unplug things one at a time, since you know the sound's schedule it should be easy to weed out.
DannyBradley;209970 wrote: The only thing that makes sense to me in the situation is ghosts. It's science.
Or you know who to callLorenK;209990 wrote: Actually, that makes complete sense.
Blind, you think it might be the spirit of that yellow tang? You should have someone come out and exorcise the tank.
Barbara;210070 wrote: Does it only happen when the lights are on? I have found that my SE metal halide bulb or ballast makes a high pitched, shrieking noise when it powers up sometimes. I attributed it to age (either the bulb or the ballast). I can't really pinpoint which device is making the noise, but I know it's the light system and the noise does stop once the bulb is fully illuminated.
Good luck finding the problem.