There is no minimum amount for the additional unique deposit
Once you have commanded your initial deposit, you could do more of them, with any amount of capital and at any time.
This necessary minimum amount to invest will be possible when the relative weight of your portfolio exceeds 4% (1% target + 3% deviation).
Important note: your portfolio will always keep cash, approximately, 1% of the volume managed for the discount of the corresponding commissions. Also, in case of having used a promotion, this amount will be kept as cash as well, during the necessary time on its legal bases, from the date the subscription was made.