Please lets try to get a better pic here. Some fast tips: place the camera lens paralle to the glass (not at an angle)... use a tripod or some kind of support... never (NEVER) use the digital zoom on your camera (always/only ruins pics) for aquarium pics... turn the room lights off and for this case (an exception) turn off the flash on your camera. Then.. set your camera to "A" (aperture priority) and you will have only a single setting to manipulate (aperture... AKA "F-stop"). Then you can "stop up" (reducing that A number) until you get a best pic you can shoot in this case.
That said... your spots if necrotic are likely a sign of inadequate water flow. mucous tunics, algae or some other settled matter has stifled some tissue and invited small infection. Increase water flow in the tank (add up to 30X turnover bare minimum) and trim the dead spots off with sharp scissors if/as needed.
Anth