How long should I wait between 30% TCA peels?

It depends on your healing or erythema time. No posted photos so can not help with a time frame.  Seek in person opinions. I hope you are NOT self treating yourself! 

This should be answered by your treating specialist. IMO and experience, I like to wait at least 6-8 weeks following a proper acetone scrubbed peel. A proper TCA at 30% takes a week to recover, and at least another 2-3 weeks before redness fades. Collagen stimulation may take up to 10-12 weeks for maximal effects, sometimes longer. This is my logic of waiting before a second peel. Im most cases, patients will require only one peel, especially if superficial pigment ,sun spots etc is the main reason for peeling. Dr Davin Lim Laser DermatologistBRISBANE, Australia.