Our Eco-columns

Our class made Eco-columns.
My Eco-columns has changed because our Elodea have started to die ever since we got our snails. I think this is happening because the snails may have eaten the Elodea. everything in our Terrarium has died I think the slug has trapped the animals trapped as ln between the soil and the slime so it can not breath. Our slug has escaped somehow from one said of the plastic (our terrarium) to the other side (underneath the terrarium). Our Fish has  also died and is laying at the bottom of our aquarium.

I think the seeds/grass rely on the soil to live. For example, The plants need the nutrients in the soil to live. The snails need the gravel to have a surface. The fish needs the water to live. For example, The fish can't breath out of water so it needs the water. The plants need the fish because the fish breath out carbon dioxide and the plants breathe in carbon dioxide. The fish need the plants because the plants breathe out oxygen and the fish breathe in oxygen.