Can you over-water a cactus?
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.
Biomimetic architecture
The Qatar Cacti Building designed by Bangkok-based Aesthetics Architects for the Minister of Municipal Affairs and Agriculture is a projected building that uses the cactus's relationship to its environment as a model for building in the desert. The functional processes silently at work are inspired by the way cacti sustain themselves in a dry, scorching climate. Sun shades on the windows open and close in response to heat, just as the cactus undergoes transpiration at night rather than during the day to retain water. The project reaches out to the ecosystem level in its adjoining botanical dome whose wastewater management system follows processes that conserve water and has minimum waste outputs. Incorporating living organisms into the breakdown stage of the wastewater minimizes the amount of external energy resources needed to fulfill this task. The dome would create a climate and air controlled space that can be used for the cultivation of a food source for employees.