PLANT AND THE PLASTIC

I experimented blowing up the outside if the stool to see if the the air was leaking out of the hole i patched up, and low and behold its worked. although as i blew it up, the air was sucked completely out of the central cylinder. thinking that this meant it wouldn't hold water, this proved an issue and i was thinking of ways to hold it open perhaps with a sheet of plastic made into a cylinder. After this deliberation i just filled the cylinder with water and, logically, the part was kept nicely rounded and i was able to fit inside a plant that will help oxygenate the water, as well as the oxygenating pills i have. the part with the water inside is rather small, i might make a small hole to see if i could fill the entire blow up stool, although not sure if this will hold itself up. i will experiment, as i would like the fish to have as much room as possible. i might cut the plant down so that it fits better, as you can see its rather large for the gap, especially as that has to also contain a fish.