And of course with IB's new "can't open a position with less than $2,000, even though the margin is $1,781" rule, Soon as you hit $1,999; you had better wire them some more. Make 'em pretty, Chris
About $5k is fine, as long as you keep in mind .. as a new trader, you may want to use it as educational income with a mere goal of trying to stick around long enough before you blow out. Also, be sure you can afford to lose this capital as well as survive long enough to pay your bills if you aren't going to be working. It takes considerable screen time and experience - which cannot be taught, cannot be found in a book and is different for everyone .. before you "figure it out".
You said it cat. One needs a bare minimum of $30K to trade on a daily basis. The $25K rule plus a little wiggle room for bad days.
It is best to trade with the minimum until you completely understand trading. If you want to go full time, then 5K won't work. You'll need 6 mos of expenses plus 25K in trading capital- that would be considered a decently capitalized floor trader in a regional agricultural exchange.