Soil
Cacti are happiest in a fast-draining soil mix specifically for succulents or cacti. Normal potting soil mixed with sand, pebbles, or perlite are also adequate for your cacti to thrive. If they have good drainage and aeration, your cacti will be happy and flourish. If you choose to repot your cactus keep in mind that cacti are slow-growing plants and will rarely need to be moved into a larger pot. If necessary, repot if they are suffering with root rot or are in need of fresh soil.
Cacti are very resilient plants and fertilizer is not necessary to promote their healthy living. However, if you decide to add some fertilizer make sure it is organic cacti fertilizer that contains more phosphorus than nitrogen and only fertilize two to three times during the growing season. Fertilizer is not needed during their dormant period in the winter.