I have small fish (I don't know what kind they are) in a 500 gallon pond (around 2000 liters) that are very hardy. They survived their previous home (hundreds of fish in a 70 gallon / around 270 liters) pond with no water circulation at all, full of algae that you can't see anything deeper than an inch) and a 9 hour car ride in a plastic bag.
I'm looking to move some of them to a smaller water basin, packed with water plants. If possible, this will be a low maintenance feature.
Can they survive by eating the plants without me giving fish food?