how do you reproduce aquatic plants

I'm trying to learn about this right now as well. Therefore, I cant be of much help. I do however know that someplants will make their own "babies" and when they are big enough, you just pull them off. Otherplants, you can divide, by cutting carefully down the middle--making two plants. But you have to make sure that the two new plants both have roots.

Maud is very right there!

Some of the plants do make new one from there leaves too! Hygro is one, a piece of leaf is all thats needed, a whole new plant can grow from those! Java ferns develope new plantlets on the leaves also, on the underside.

Bulb plants tend to make new ones at the bulb itself.

Anacharis is easy. it just keeps growing longer and longer. You can pinch off the new growth and walla a new plant. It will also send out shoots off the main stem.