Renting room per day
Consider that you are giving up the use of the space for an entire day for only $30. If you take those days off anyway, you are coming out ahead. But over time, you want any other practices that share your facility to enhance, not detract from, your business as an MT. You can't make a living by renting out your space for $30/day. What you are proposing to do will be a good learning experience/test case. Long-term, you will need to revise your business model so that adding additional practitioners/therapies won't negatively impact your massage income.
People that come for acupuncture probably won't switch to massage, and vice versa. However, be prepared to work out how you would each handle situations in which one practitioner's client decides to start seeing the other person instead (i.e. one of your massage clients decides to just get acupuncture from now on, or vice versa). Better to have those discussions in advance (and a WRITTEN AGREEMENT covering rent, policies, etc. -including such situations) before the acupuncturist starts practicing there.
Another consideration: one day per week isn't much time for an acupuncturist to build a practice or earn income. At some point they will want more time, different days, or whatever else they think will enable them to grow and become more successful. This could also become a reason for them to leave. Consider that possibility and don't let yourself rely upon their rent. How you will handle such things in the future should also be covered in your WRITTEN AGREEMENT.
Last, don't proceed to rent the use of your space without a WRITTEN AGREEMENT. Have it reviewed by a professional (lawyer, business advisor, etc.) before showing it to your prospective renter. This step takes some serious thought and a bit of effort, but it may save you MONTHS of aggravation and preventable expenses later on. It will also serve as a model for future rental agreements with other practitioners, so you won't have to start all over again the next time.