How much additional weight do I need to add to my floor machine for honing marble floors? I get different answers from different manufacturers and suppliers.

The addition of weight will depend on a number of factors. The type of machine you have, how many diamonds you are using, the size of your drive plate, etc, etc. This is the reason you are getting so many different answers. As a general rule of thumb, weight is added at the lippage removing step and as you move up the weight decreases. I have found that for most marble floors very little additional weight is required. Most of the time I can hone and polish a marble floor with no added weight at all. I would suggest you experiment and use what technique works for you.

TIP The more weight you use the faster your diamonds will wear. Let the diamonds do the cutting and avoid excess amounts of weight on marble.