Finding suitable sand can be a problem. Salt, alkalinity, clay or other
contaminants can be a problem not to mention variability from brand to
brand or particular sand pit. Yes, you should be picky, particularly
for plants in containers where mineral buildup can be a problem.
I have gone to using silica sand. You can find a fine grade used for
sandblasting at most building supply stores. "4060" is a fine
grade--60% retained on 40 mesh or coarser. It is clean and had a pH of
around 5 when I tested it. It does pose an inhalation hazard
(silicosis) but just be careful, wear a dust mask, dampen it slightly
before using (I recommend this also with perlite which also is an
inhalation hazard), mix it out doors on a light breeze day. Practice
common sense. Use the fine grade. There is a coarser grade but this is
not the sort of sand you would find where CPs are growing in the wild.
I have used "play sand" in the past with no noticeable problems growing
Sarracenias but some Drosera seem to do poorly. A couple of the growers
in the area reported problems (some plants died) with "builders sand".
I tend to repot every two years, to divide some of the fast growing
Sarracenia like S. rubra and also to remove grasses, sedges and weeds
that have invaded the pots.
Good luck.
-Scott
svergara@pacific.telebyte.com