Just a thought.
The problem getting stuff in Canada seems like an opportunity for someone -in- Canada.
Tissue culture and standard hydroponics techniques could produce plants that one couldn't grow well in a fish tank.
There should be some really great buys at an RCMP auction, on hydroponics equipment from pot houses being busted.
Substrate can be gotten in large quantities and re-bagged or ordered by the pallet and shipped out with little extra work.
For Turface you've got two distributors in BC.
Premier Pacific Seeds
Multiple Locations Serving British Columbia
distributes calcined clay and filter materials.