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.
Houseplant care
Since almost all of the air circulation (transpiration) happens in the roots as does almost all of the energy production, the roots must be able to breathe easily. Overwatering will drown a typical houseplant. The air is pulled through the soil by the breathing of the roots. Air must be able to flow through the soil.