I dyi my ato also. Kind of still in the process of making it or I would offer up a picture. Unfortunately I don’t have a second floor where I can accomplish what Spridle drawing does or I would of definitely gone that route. But under my tank offers plenty of room to accommodate a 7 gal aquatainer available at Walmart some fittings from HD and a bubble magus float switch for a gravity feed system, total cost around $60. No modification just screw everything together and worked. I’ll get pictures when i get home if you wish.