I put my rock collection on our manhole cover - and some pot plants also
You will need to 'scrub the deckking' every month or so with v. mild solution detergent / bleach to get rid of slippery algae - sounds like a job for the PIRATES (DCs) or get a power hose and a big pair of wellies!
also make sure that the grooves allow you to have water run-off away from the house - a very slight incline in the decking is necessary also - so water will not pool, and will flow away from house. Algae grows on the wet wood, and it's what causes the slippiness. Keep it clean = no slips.