We added bicarbonate of soda to the water so there would be lots of carbon dioxide to promote photosynthesis
Two spatulas each so its a fair test.
Mix thoroughly and then add the pondweed.
Make sure you use 10cm of pondweed each so its a fair test.
Weigh the pondweed down with a paper clip
Now put it by the light and see the bubbles of oxygen coming off.
