Creating a Water Garden with plastic does not have to be an expensive project. However, do not cut corners with your liner.
You do not want to use a swimming pool liner or any roofing product because these could kill any fish that you may want to put into your Water Garden.
It is better to go ahead and spend a few dollars extra and buy a plastic liner for your Water Garden; a plastic liner is cheaper than a prefabricated liner. You can also ask your neighbors or friends about some water plants if they also have a Water Garden. Plants in Water Gardens grow fast and need to be thinned out every year so that the Water Garden keeps its beauty. If your Water Garden is very large, you can get some plastic trash can lids and drill a little hole in the bottom of them. You can keep these lids floating by using a noodle. These are the same thing that you play and float in a pool with. These will keep your trash can lids floating and will be great for those water plants. You can also use potting soil and mix a little-unscented cat litter in with the potting soil. This will save you money because you will not be buying the expensive soil for water plants. There are a lot of ideas about creating a Water Garden on a budget available online. You will be able to find a plan that will fit your budget and have that beautiful Water Garden ready to go this spring.
Source of Information on Water Gardening