Yeah that sounds like a good setup. With just one turtle you’ll probably be able to go weeks and maybe even months without cleaning the filter or water changes (but you will need to add water). It can last longer if you feed your turtle in a separate tank/container because they’re messy eaters, but I’m way too lazy for that. When I clean the filter (like once a month) I take out all the sponge pieces and spray them down with a hose and I try to follow the recommendations on the packaging for replacing the carbon or ammonia filters. Winter it rough because I usually won’t clean the filter for about 3 months because I can’t take everything outside to clean really well so I just do water changes during winter.
Thanks for explaining that to me. Do I need a water heater as well? I’ll have a uva/uvb and heat bulb. I want to get everything ordered this weekend. I plan on keeping it fairly simple and clean, similar to your setup. Bare bottom, floating dock and maybe something decorative. I wouldn’t mind a couple aquatic plants but wouldn’t I need something on the bottom to have plants?