were do the aquatic plants come from? do they naturally come and grow in the pond or do u have to plant them? if so can u choose what aqutic plants u want.

excuse me...but i am new to the whole pond thing.

Both. They will eventually and naturally show up on their own. However, they may not be what you want, so you can introduce what you do want. That's not to say that the natural ones will not show up on their own even if you plant though.

on your opinion what are some plants that grow slow and dont spread s quick...that are recommended for ponds. (some submerged species)
on your expert opinion

and were can i obtain these plants?

Some examples of plants suggested by Bill Cody at Pond Boss Conference IV were water iris, sweet flag, spike rush, lizard tail, arrowhead, water arum, pickerel plant and marsh marigold. He likes these based on their max height, rate of spread and ability to control.

Stock Seed Farms is one place that sells a large variety of aquatic plants.

Try this http://www.dec.ny.gov/docs/water_pdf/ch6apr05.pdf

what about submerged aquatic species? can u help me out there?

http://plants.ifas.ufl.edu/category?filter0[]=13