Adding tie down points with no access under trailer

Hey guys looking for some help. I need to add some more/better tie down points to my 26ft weekend warrior. The problem is the spots where I need to add the anchor points to have tanks for fresh and waste water directly below although the there is a gap of a few inches separating the floor and the tanks. Has anyone else ran into this and came up with a good solution to bolt them down. Maybe using toggle bolts or…….? Any help would be greatly appreciated. The stock anchor points are extremely cheesy and I’m starting to rip them out of the floor.