It is always worth remembering that the health of the plant will depend on the quality of the soil in the pot.
If the soil has run out of nutrients or has lost its original properties, it needs to be replaced.
First of all, it is worth paying attention to the plants themselves. If they do not look their best and are constantly sick, then replanting them in new soil may be one of the best solutions.
It is worth visually assessing the quality of the soil. The topmost layer is of interest. If the soil has become dense and resembles a crust, then it is worth thinking about replacing the soil.
Yes, this advice may seem a little strange, but trust your own sense of smell. If the soil smells normal, then you can calm down.
But the soil that needs to be replaced has a pronounced unpleasant odor.
These signs are the most reliable, so they are worth paying attention to.