I just bought a Black Oscar about 3 mos. ago. He was doing all fine up until a month ago. Every time I turn on the lights he would sink to the bottom of the tank and lay on his side. When I turn off the light he would slowly get back up from the bottom and swim around. I am wonder if he might have some sensitivity to lights. Someone had recommended to use a blue/black light instead of a clear light. I've never had this happen to me before as I've had several Oscars before and this is my first on ever owning a Black Oscar as I was curious about this color/breed. Is there anything I can do to get him to stop sinking to the bottom like he is dying whenever I turn on the light??

I would say maybe try using a softer light. i only run my tank like for like 4 hours a day when im up during the night. I would suggest run the light on during the day when you have a lot of light already in the house unless he is in a dark area to get him used to the light and try that

lol, we were discussing a quite similar situation a little earlier:
www.oscarfishlover.com/oscar-fish-advice...ecause-of-new-lights

mine do that too but they are in training right now to be able to have it on. my poor pleco never has to clean cause i never turn the light on! lol

whereas lights aren't actually a necessity in a fish tank, they are more for our benefit, it's obviously nice to be able to see your fish. If this problem persists, try putting something in the tank that will enable the Oscar to hide when the lights are on, maybe a large piece of wood, or a large plant pot.

It may be just a case of you leaving the lights on and letting him get used to it. If you automatically turn the lights off every time he lays on his side, he'll never get used to them. Oscars are very strange fish, I've never come across fish that act quite the same as them.