Cleistocactus strausii
As a houseplant, the Silver Torch cactus is an easy to take care of so long as over-watering is avoided. To naturally simulate the porous effects of the sand in its native habitat, it's important to ensure that excess water will not pool in the soil, causing the roots to become water logged.
This plant’s native habitat does not have winter, but when temperatures drop to the low twenties, it can exhibit signs of tip frost. 
The Silver Torch cactus is most susceptible to 
mealybugs 
and spider mite.
Potting soil
Some plants require potting soil that is specific for their environment. For example, an African violet would grow better in potting soil containing extra peat moss, while a cactus requires sharp (i.e. plenty of) drainage, most commonly perlite or sand. But potting soil is not ideal for all contained gardening. Insectivorous plants, such as the Venus flytrap and the pitcher plant, prefer nutrient-poor soils common to bogs and fens, while water-based plants thrive in a heavier topsoil mix.