Water Hyacinth and fish OK for rain catchment drip irrigation?

Hi, I'm planning to build a rain catchment drip irrigation system for my small-plot urban farm.  I just stopped by the botanical gardens, and they were selling water hyacinth, so I bought some.  They claimed the plant, which floats like a lily and blooms, cleanses the water.  Two questions:

1. Does anyone know anything about growing water hyacinth in rain catchments?

2. How about putting fish in the catchment to increase nitrogen in the water for plant irrigation?  If so, any particular fish recommendations for a clear bin in outdoor conditions?

Thanks!
Josh