Wow Ken thanks for the help....ummmm
my summation is that I did nothing and I now have a problem of yellow leaves at the centre of the plant getting worse (after doing nothing for a year)
I then tried to do something after some internet research and was hoping that somebody here may have had a similar experience that could tell me what they did that helped
It seems that you have healthy plants and have left them to stay healthy and obviously your soil is working out for them...I don't have this situation and am hoping to solve this
I'm thinking that doing nothing will result in nothing when you actually have a problem
But hey thanks for your advice of doing nothing???

I have never grown inkberry, but I do grow blueberries here in Madison, WI, and I have to do periodic pH testing to keep them green & healthy. Inkberry is related to holly, and holly is said to prefer soil with pH in the range 5 to 6. The method that I am currently using to measure soil pH is with dye indicators. Using bromocresol purple indicator, it is possible to see pH in the range of 5 to 6.8. A test solution will be yellow when the pH is between 5 and 5.5, and it will be purple when the pH is between 6.4 and 6.8. You would take a one tablespoon sample of dirt, and mix with enough distilled water to make a slurry. Run this solution through a paper filter, using a funnel, and collect about one teaspoon of filtrate. Add just enough dye indicator to see the solution turn color, and note the color. If chlorosis is causing the yellow leaves, and you have put down sulfur to lower soil pH, you should see positive results in 4 to 6 weeks.

Thanks Ericwi - that's what I was wondering ie the timeframe to correct the issue
If I am still getting yellow leaves in about a month I will know that I haven't corrected the soil adequately
I read yesterday that iron chlorosis occurs to young new leaves but that magnesium deficiency shows up yellow in the older leaves (as in my situation)
I'm hoping the hollytone will help correct some of this but has anybody heard of what I can use to spray the existing leaves because apparently this can prevent them going yellow ie spray with a magnesium mixture (ie treating the soil will help prevent future leaves going yellow but that spraying existing leaves will keep them green)

I know nothing about Inkberries but they are evergreen Ilex sp. ie they ARE hollies, not just related. The Holly I know, Ilex aquifolium, also produces a lot of yellow leaves and sheds them in early spring. Although they are evergreens they still lose leaves on an annual cycle and the older ones will be the ones to go. So, quite possibly there is nothing at all wrong with your Inkberries. Chlorosis tends to show as yellowing between the veins. Normal yellowing before the leaves are cast is less specific and tends to be all over.

Thanks florauk
The leaves appear yellow at first and then get brownish/black dots over the leaf but they are the older leaves so perhaps they are just shedding? though this makes the bush look 'thin' which is why I trimmed them to help thicken up the growth... I think the inkberries have a tendency to get leggy and thin looking if you let them grow without trimming every year
The plants seem overall healthy though since there is lush new growth all over the ends