Areas around plants, and those under wood or rock, I leave alone. The open areas which basically are along the front can be lightly cleaned (as described in posts 2 and 3 above). In some tanks I leave it alone. It somewhat depends upon the fish, and the plants. The organics that accumulate in the substrate get broken down by bacteria and this provides essential nutrients for live plants. CO2 is the primary nutrient that naturally occurs primarily from the organics in the substrate. Provided you do not have too many fish, or too large fish, or feed too much, waste on the substrate should not be an issue.
I clean new play sand in a bucket, just a small amount at6 a time (around 5 cups), under the tap in the sink in the utility room (you can do it outside and run the waste water into the garden). I don't clean new sand too thoroughly as it is just fine dirt and it will settle out and not harm fish or plants.
Play sand is just about the best sand for an aquarium. It looks natural, and is the least expensive without question. I am lucky to be able to get a dark grey mix (Home Depot here) and some stores have a buff tone mix. Either look very natural. There is nothing wrong with pool filter sand as such, but never use white; this is stressful for most fish because it is completely unnatural and fish are highly sensitive to light. There are aquarium sands but these are quite expensive compared to play sand. I changed over all my tanks some 8 years ago and wish I'd done it sooner. Play sand is very safe as it is the most refined of the industrial sands.
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