Yeah, it has the effect of driftwood; tannins, lower PH, etc. The effect on PH will be dependent on how good your buffering capacity is. I've used the indian almond leaves and regular oak tree leaves. Gives it a nice, natural, blackwater look.
What's your KH? If your have a decent buffering capacity you could add an entire tree and your PH won't budge.

cali what is the fish in your avatar??

is that RTM a SA cichlid???