Question
I live in central Florida and have St Augustine grass, I have clover and I believe dollarweed all over my lawn. What is the best treatment to remove these weeds.

Thank You

Answer
First of all, dollar weed is an indication of over-watering. Once established it is difficult to kill because it forms a 'mat' of underground roots. "Image" (active ingredient: imazaquin) will reduce the dollar weed population but will cause the turf to turn 'yellowish' but that is temporary.
'Atrazine' is effective but slow. Products containing this a.i. are usually restricted to certified applicators and barred from use during certain times of the year.
"Speedzone" (FOR ST. AUGUSTINE) contains three a.i's and one of them is quite harmful to Floratam. The manufacturers have marketed a formulation that is comparatively safe for St. Augustine and I would expect that there will be additional precautions for 'Floratam'.
So, reduce irrigation to the bare maintenance level and use a chemical which you can measure and apply accurately. Formulations of plant killing products are tested and vetted carefully. They must be accurately applied to obtain optimal results. Use a sprayer that will give a fairly even pressure from 'full' to 'empty', use a fan jet and mix a dye in the solution so that you can track the uniformity and completeness of coverage. My usual advice is:
  "Do it professionally or have a professional do it" because plant killing chemicals do not forgive.