1. As far as I know, any labeled "filter sand" should be OK. Obviously, there could be exceptions, but I don't recall hearing of problems.

2. Do NOT use sandblast sand (typically, too coarse) or 'play sand'. Play sand and masonry sand usually has too many 'fines', and will plug the laterals and damage the multiport valve.

3. Be careful with your pump sizing, and piping. A TR-140 needs 100 GPM to properly backwash. Very old pools often have undersized piping. If you try to backwash a TR-140 with, say, 60 GPM, you'll fail to clean the sand fully, and will gradually loose filter capacity. There's no point in installing a filter that is too large for you to successfully backwash.