Most day trading requires more of an investment than $25,000.00 but there are some things you can day trade in with less than $25,000.00
Day trading forex or futures requires less capital and investing than other things you'd day trade so yes it's possible to invest in day trading with less than $25,000.00
Be sure you know what you're doing though or hire someone that knows what they're doing when day trading because it's very easy to lose money in it.
If you know what you're doing and do it correctly then you can gain lots of money on your investment when day trading.