Old pleco getting white spots
I have a pleco that I’ve had for 17 years, so he’s quite old. He’s about 10 inches in length. He lives in a 70 gallon tank with very few other fish - the only others left are some loaches and a small frog. I feed them 1 algae wafer and a good-sized pinch of flake food once a day. The tank doesn’t get cleaned or water changed as often as it should but I just did it about 2 weeks ago. Water temp is 76. Nothing has changed in years - some tank, same location, same food, no new fish introduced.
Recently he’s started to develop pale spots. The area around his mouth is completely white and now he’s getting pale spots all over his body. There doesn’t appear to be anything growing on the skin or any damage to it, it’s just like the color has bleached out in those spots. Does this sound like an infection or condition I should be treating or could it be due to old age?