Rollover SD-IRA to Solo 401k??

[Erin M.]

Hello BP'ers! A few questions for the tax experts. For reference, I work full time and have started buy and hold rentals for long term investments/wealth building. I currently have a Roth SD-IRA. I'm finding the unleveraged ROI on rentals to be subpar, though want to avoid UBIT from non-recourse loan income. From what I've read, I may be eligible to start a solo 401k if I report income from a business outside of rentals, ie- consulting or services offered.

1- Is there a minimum amount I'd need to earn/report to qualify for the solo 401k?

2- Is there a way to roll over the Roth SD-IRA to a solo 401k account?

Thanks in advance for any suggestions!!