Yep, still working on creating my in-class ecosystem models. Barb tank is almost ready for completion. The plants are planted, the tank is cycling with a handful of feeder guppies until next week. That's when the community of fish from my home summer tank will be moved back to the much larger class room tank.

So now I work on other parts of the ecosystem, which means invertebrates. Which commonly available species do you all recommend to mix with Tiger Barbs and nippy Tetras? Preferably one that won't eat all the grass-type plants please - or eat the Neons as a snack!

Amanos are plant friendly and are big enough so they won't be eaten by the barbs

Get a dozen feeder shrimp, they tend to be ghost shrimp. They are cheap and plant friendly and will more than likely breed for you.