Guppy Grass / Najas Guadalupensis This is a great plant capable of growing in most tropical aquariums. Can grow in substrate or free floating. It is good for fish fry and Shrimp. As seen in my tank in photos here it can grow quite large. It gives a great surface area for your algae eaters to eat biofilm. My Shrimp, Snails, baby Plecos and even my guppy fry like living among this plant and thrive on it. Sold in 50g bags of Guppy Grass, which is plenty to get growing and establishing in your tank.