Just wondering about tanning beds?

I would like to resume tanning. I dont go all that often ( like 1 time every 2-3 weeks) for my acne and was wondering how long I would have to wait before doing it again. I am breaking out really bad and with not being on b/c pills anymore I dont know what to do. I will remember to ask when I go for checkup on Wed. Thanks in advance for replies! -Sue