Make your own reusable tray for a homemade volcano. Use ceramic tray for potted plant. Hot glue gravel and plastic dinosaurs around edges leaving circle in middle. Glue plastic bottle in center. Then build volcano from sand and put appropriate ingredients in bottle to create volcano. When done rinse everything and repeat another day.
Build a Baking Soda Volcano Fill the bottle most of the way full with warm water and a bit of red food color. Add 6 drops of detergent to the bottle contents. The detergent helps trap the bubbles produced by the reaction so you get better lava. Add 2 tablespoons baking soda to the liquid. Slowly pour vinegar into the bottle. Watch out - eruption time!