I'm 66 and I'm going from freshwater to salt I'm a disabled/retired veteran I do my ro water in 3 gallon containers and dump them into 5 gal containers. I do my water changes (65 gal tank ) with a pump 5 gallons at time. Sorry to see you go and yes I have major back problems as well. Can't stand still anymore,can't sit in a desk chair and have to use a foam piece in my recliner. If you love the hobby keep on trucking. Go to a smaller tank if need be