Changing Substrate For Plants

[Mariposa]

My tank's been up and running for almost two months now and I want to switch it to planted tank (I wish I had known it was even a possibility when I set things up). I was told to change the substrate to one that's finer with perhaps some laterite in it, which I will do ... but will it ruin my cycle? Will I have to recycle? Should I wait a few more months until I would be re-aquascaping anyways to minimize stress on my fish?
Here are stats: 21 gallon (U.S.) tank
9 rasboras in there now
two pearl gouramis coming soon
Thanks!

 

[zig]

Most of the benificial bacteria will be in your filter, although removing the entire substrate and changeing it may cause a mini cycle, but the filter should catch up pretty quick.

You could always remove the existing substrate in stages over a week or so and that way minimise the risk, rather than removing it all at once.

 

[Mariposa]

Thank you so much!