The palm is around 12' tall. The trunk's circumference is around 1 1/2'. Fronds appear to be healthy. Few have the black soot, indicating aphids. Plant has been treated.
That would be a question for your local cooperative extension agent who is familiar with the area and others who grow coconut palms. Here is info on how to find your agent:
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm
https://www.gardeningknowhow.com/edible/fruits/coconut/growing-coconut-palm-trees.htm
How to plant coconut tree? & It's good growth
We have some articles that will be just what you need to learn what care that coconuts require.
Read this collection of articles for information on coconut palms: https://www.gardeningknowhow.com/category/edible/fruits/coconut
Hmm, I got a sprouted coconut from near a river which his father had reaaaally sweet coconut water, I took it home but my mother always let the water with detergent, bleach and softener get his way into the yard, so much that the drainage of the soil (clay soil, but that's not a problem I have a lot of compost and wherever I mix it it improves the drainage a lot) can't take all the gray water
There are much greater concerns than the flavor being transported through the tree! That soil will be far to alkaline for much to grow well. Those detergents and salts can be toxic to plants. If your yard contains quite a bit of detergent content then you will be best to grow them in large container to avoid contamination.
Here is an article that will help:
https://www.gardeningknowhow.com/edible/fruits/coconut/growing-coconut-palm-trees.htm
How to increase the thickness of the shell without breaking the coconut fruit. And which chemical or fertilizer is used to thicken the shell.
Start with foliar applications then progress to granular. They are heavy feeders and they need lots of water.
https://www.gardeningknowhow.com/edible/fruits/coconut/fertilizing-coconut-palm-trees.htm
https://www.gardeningknowhow.com/edible/fruits/coconut/when-are-coconuts-ripe.htm
I bought a new coconut tree from morrisions and was wondering what is the best way to take care of for it to last many years? Also would you know where my tree has come from , is it grown in the UK or was it brought from another country :)
These articles should help:
https://www.gardeningknowhow.com/edible/fruits/coconut/fertilizing-coconut-palm-trees.htm
https://www.gardeningknowhow.com/edible/fruits/coconut/growing-coconut-palm-trees.htm
Two coconut trees side by side more than 8 years old growing fronds well and twenty feet tall now but no flowers is seen
Likely, the nutrient profile of the soil is not as it should be. Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm
https://www.gardeningknowhow.com/edible/fruits/coconut/fertilizing-coconut-palm-trees.htm
The coconut plant in my house produces about 4 fruits per bunch even though other coconuts in the same vicinity are producing more fruits, in certain cases 20 or more. What might be the reason?
Is the tree really inside your house or do you mean "at my house?" They are not really ideal plants for indoors. Here are some problems with coconut trees in this publication.
https://www.gardeningknowhow.com/edible/fruits/coconut/coconut-tree-problems.htm