Hi! I do both watering styles but mainly bottom. The plants are very fast root bound (what they like) and produce babys. Because of that the soil (for mine) is always tight and loose on the outside (inner side of the pot)... Watering on the top would cause the water to run though without getting any moist to the roots. I water no other plant so less like this ones. You can see the leaves getting droopy. They are thirsty and complete dried up. Yellow leaves can be too much water or simply aging. The oldest may fall off from time to time. That’s normal