Leaves rapidly turning yellow .Please give me some advice.

[Becca]

I agree, check the roots! Good roots will be firm, bad ones squishy! I would also say squishy brown roots are bad, but some potting mediums can turn the roots a tan/brown color, so if they are tan/brown and firm then the roots should be ok. You will need to trim off any bad roots. When was the last time you repotted them? What kind of lighting are they getting?