could i do Eco complete and then Flourite Black Sand on top?
ok if i had cory in the tank with the sand could the uproot the plants...Either one would work. I use both independently, and haven't had issues with plants popping up. Just put 3" of substrate, bury stems deep, and avoid animals that root around in the substrate.
FYI when first planting, you'll have plants occasionally float up. It happens, regardless of substrate type. Once they root, they're there to stay.
And Eco and Flourite Black Sand wouldn't mix together ...well, they would, on their way to switching places. The sand will end up on the bottom and the Eco on top. Eventually.
Cories can and will uproot anything before the anything is rooted, regardless of substrate. Any large-ish bottom-feeder can. But as long as your substrate grain size is a good bit smaller than epoxy-coated clown puke available at any LFS, you're all set.ok if i had cory in the tank with the sand could the uproot the plants...