Growing your real estate portfolio?

[Paul NA]

I've read numerous postings on here on how certain individuals have grown their portfolio to 20, 50, 100, and some over a 1,000 apartments.  It would be nice to find out how folks have been accomplished that.  On a personal level I have reached 6, but almost feel like I'll be tapped out of cash after another one I plan to purchase.  The current properties I have produce decent cash flow, but really have to wait 12-months to use that cash to buy another.  Most banks require 25% down on investment properties, and around here the condo/apartment properties are typically $150-$250k range.  

Using hard money lenders wouldn't make sense for buy and hold for rental purposes, and traditional banks require the above mentioned equity on investment properties.  I also don't have any big investors that could support me.  What other options are out there?

Appreciate the feedback.