OK - deposited 900, now at 1700 - how much have you "lost" thus far, or are you green? I would try to take 50% of whatever profit you have out until you are even in your own personal account. From there, I'd take out 25% as you go. Like with the current situation, I would take out $200 and leave the rest....just put that $200 aside in the event you hit a wipeout condition.
Once you get totally "on profits" and playing with the house money, let it grow....all IMHO
Mama and Daddy always said it's how you play the game - trade to trade well and the rest will fall into place ;-)