The FEI has made available two FREE PDFs that you might want to read. They're both about arena surfaces, aka footing, and they are based strongly on research and fact rather than advertising hype and trainer opinions.
They may help you make the right choices for your arena and/or make you more aware of the concussion your horse absorbs with every footstep over bad surfaces.
Both are available as downloads from this one link:
While you're there, you might find the"FEI Sustainability Handbook for Event Organisers"useful, too, especially if you organize events in your area. It's designed to "help reduce negative environmental impact of the events and create a positive social and economic legacy."