Is it a nitrogen deficiency? or over watering or underwatering?
Also, do you think I could fertilize it with a 20-20-20 that is for orchids?
What is this problem? Anthurium Yellow spotting
Gosh, I' surprised no one has replied ..... I wouldn't fertilize until I knew what what causing it..... may be a water issue..... I don't grow those, but this will bump your query back up and hopefully someone more knowledgeable will see.
Could be a lack or air flow or humidity. Check the undersides of the leaves for any bugs. If non of these seem like the problem it may just be an older leaf at times once the leaves age enough they turn fully yellow and fall off. But hard to say for sure. I could think conditions first.
It looks like a lack of water since the yellow is on the outside going in but?? You might want to go with something more like a 10-10-10 so it doesnt get burned if it is super stressed. If it is completely dry, I would water it first and wait a an hour or so before fertilizing.
I bet it is humidity. They are in the house and we do have a dehumidifier that doesn't help. I fear putting it in the greenhouse because right now with the high temps. and then in the winter it could get down to 55 degrees. I did not think it liked anything over 80 degrees or so.
I was thinking some type of blight or mosaic virus or whatever.
Maybe I will try the greenhouse for a change.
-thanks for bumping this up for me.