If you have a taxable income of $50K and convert $60K to Roth, which adds to your taxable income, making your total taxable income $110K, how do you pay zero in federal taxes?

It’s paid off, I would “like” to leave it that way & maximize the cash flow while paying down the heloc between the rental & other income.  

-----------------------------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Would the federal tax liability be $140k at year 5 for the sale, with long term capital gains (ignoring any Net Investment Income Tax)?

I have over a hundred rental units I own and operate in Utah everything from homes and condos to larger multifamily.Salt Lake County has higher property taxes and is basically built out already and Ogden even though you can find good opportunities in the long run it won't be able to compete with South Utah County or Eagle Mountain. 

I’m not looking to retire early or replace my income through rentals—I just want to diversify our assets.

Investing in multifamily properties offers steady cash flow, diversification, as multiple tenants reduce vacancy risks and provide consistent income.

If they notice you have another house and your debt to income can't cover it.

It will have to be a pass through/disregarded LLC to keep the tax payer the same and the 1031 valid.

I just started using it and so far the owner info matches up with the county tax info.