Sounds like mites or scale, but without photos, it's just a guess. Treat, accordingly (Neem oil works well.) Never ever water from a tray. Water from the top, allowing the water to drain out. Do not have your tree sit sit in a "puddle". No need really to prune citrus. Again, without photos, impossible to tell you specifically what would be best for your tree. Patty S.

Took pics. Last year the foliage and fruit was so abundant that I could not see into "it" But now having pruned it and taking pics...I see that it's actually TWO trees! Here is the pic of one trunk... Clearly the ground underneath needs to be cleaned out and all the ferns removed. There is also a little "volunteer" tree growing out of it that needs to go. I do feel that these trees were doing better when it was left alone....the previous owners were there 8 years and never fed it or paid much attention to it. All the trees are starting to fail....could they be too old...(there are also two pink grapefruits, some sort or orange and some sort of "quat" maybe a loquat. .one of the grapefruit trees was great...and now that seems to be dying...but I think that's because the original owners put a tomato cage around it when it was a tiny tree and it actually cut into the trunk...it's wounded)

Mike, They are called Air Pots. https://m.youtube.com/watch?v=hsakG5JRUcI Some people love them, others consider them a waste of money. A friend of mine owns a hydroponics store which caries them. He has been "bragging" about these things since day one. He grows multiple things inside his store and exclusively uses these air pots now. He has shown me root balls of his plants after being in the air pots for a year or more and they were mind blowing. He told me since my air layers had "virgin" root systems that I would be very happy letting them grow and mature in this type of pot versus hard wall pots. After seeing his rootballs I had to do it. So that's how I ended up with them. I am VERY happy with them, all of my citrus are thriving in them. I am very happy.

Hello. First of all the pH of your fertilizer solution is very important for in pot trees. Then too, anything can affect nutrient uptake from a lack of it in your choice of fertilizer, the temps your tree is exposed to, the amount of watering and how often you water, root rot, pH, and light eat.. Have you tried discounting each of these [problems at a time or even if you post more info it would help. Tell us What the temps have been both day and night? How much sunlight that tree gets? How often you fertilize? If that is a soluble one or organic? Does it have potassium in it? How old is that mix? How often do you have to water? How do you know when to? I always start with happy roots then fertilizer.If the roots are not happy, then any fertilizer with a good pH solution will NOT be utilized by any plant with unhappy roots or a weak root system..