According to Baidu picture information, the cactus can grow to 5 to 10 centimeters.

According to information on the Bilibili website, the Poseidon cactus is the Michalovich cactus. The size and growth rate of the Michalovich cactus depend on a variety of factors, including light, temperature, humidity, soil, Fertilizer etc. Generally, the size of Michalovich cactus is between 5-15 cm in diameter and about 5-10 cm in height.

If given enough light and an environment with the right temperature, Michalovich cactus can continue to grow and become stronger. Under ideal conditions, its size may exceed 20 centimeters or even more. But be aware that over-fertilizing or over-watering may cause it to grow slowly or become unhealthy.