I have found this to be true but much more so if the sand is too fine. for example the capilliary action sand exercises in wet seasons can cause bacterial rot on Oncocyclus Iris. However, an insulating layer of gravel top dressing usually gets round this problem and, for most other plants I have grown, it is not an issue -provided the sand is coarse enough. Peter (UK) On Fri, Jul 13, 2012 at 6:22 AM, clayton3120 clayton3120 < clayton3120@cablespeed.com> wrote: > Sand, on the other hand, is heavy, and can very well close the porous > space you just created by adding a larger conditioner such as > pumice. In my climate, during the rainy season, sand , when it is > wetted, is nearly impossible to dry out, considering their is little > sun or heat to evaporate the moisture. >