Truck TV Dust in cover bed; solution options?

Gliddenwoods

I tow my TAB 400 BD Lite with a F-150 with a flat bed cover. When driving on dirt & gravel roads I get a lot of dust in the enclosed bed on all my camping gear. Last week's camping trip on some fine sand/clay roads made a real mess on all my gear! I have researched several optional solutions including bed floor covers, tailgate hinge covers and tailgate seals.  
Does have any experience with solving this problem and what product(s) do you recommend?
Thank you.

Bayliss

@Gliddenwoods, without knowing what cover you are using, or how it is attached/configured, if not coming through the tail gate edges, is there any possibility that dust is entering through the anchor/tie down openings on the bed rails?

CrabTab

@Gliddenwoods, You could try to tape off different areas to determine where dust is infiltrating. Once you have it figured out spend on a solution instead of throwing money at 'potential cures'.

N7SHG_Ham

Easy solution is a big blue tarp, put it in bed, load bed and fold over top and bungee. Crude, ugly and effective.

GatorEgg

The tailgate seals helped me the most.  The one along the lower gap between tailgate and rear lower bed did the most.

Tabnero

https://extrudedsolutions.com/
I bought esi tailgate seal from Amazon and it fixed the issue for me