I find the plants in the pet shop to be poor quality and overpriced, but maybe that is just my area pet stores. I've also noticed they sell quite a few plants in the fish section supposedly for aquariums that are not true "aquatic" plants. For water plants I would try a pond and garden store. You can order plant on ebay too if you are having trouble finding them.
Last time I got mine I got it from a local koi/pond shop. I got it when it was super fresh. In fact, they hadn't even unloaded it from the boxes yet (it had just come in the day before)
Ralpheal, "The 'L' is silent." Frankie, "Young at heart."
Water hyacinth is banned in some states, mostly those that don't have winters too cold for it not to survive. It's becoming one of the few aquatic plants that's easy to get at garden shops that carry plants for ponds. It will grow and spread quickly given the right conditions (sunlight and warmth).
"You become responsible, forever, for what you have tamed." -Antoine de Saint Exupery-