Like just about everybody here, I am blessed/cursed with MTS. The affliction has peaked several times during my life, as tanks mysteriously multiplied until I would wake up realizing that the fun was rapidly disappearing due to the volume of work required. I would slash my tanks down to the bare minimum...but a couple years later the cycle would be well on its way to repeating itself. There were periods of my life during which I didn't even acknowledge or admit that I was an aquarist...because I only had 2 or 3 tanks at the time...
As I approach full retirement, I am determined not to let it happen again. I only have 7 "permanent" tanks right now, not including things like quarantine tanks or fry tanks, as well as a growing number of outdoor stock tanks during the summer only. Two of my tanks, a half-filled 30g and a 20g, are located on the ground floor of my little bungalow, and those dang things consume far more of my time and effort than the approximately 850g in the basement; I am actually still using the stone-age technique of hoses and buckets upstairs, whereas the basement tanks are all completely plumbed so that I can change water simply by opening and closing the correct valves.
The upstairs tanks are scheduled to be incorporated into this DIY plumbing nightmare this coming summer. My wife would be very unhappy to learn that there will be holes drilled into the floor upstairs in two places to admit water lines. Since I love her and want her (and, by extension, me...) to be happy, my solution is simply not to tell her. I will likely be long dead by the time she discovers the discreet holes in the corners under bookshelves; or at least, I will likely be dead shortly after she discovers them!In the meantime, she is very fond of the turtle and the small fish inhabiting the upstairs tanks, and has no reason to think too hard on what their existence entails.
MTS; there is no cure, merely treatment of the symptoms. Don't get too carried away with dosage, i.e. don't overdo the work load. You are much better off limiting yourself to the number of tanks that you can comfortably maintain without the pleasant task morphing into unpleasant drudgery. And it isn't necessary...or desirable...to keep every species of fish in the world, or even every species you think you "must" have. I have a number of "favourite" fish species which I have never kept and never will keep. Having a moderate number of fish and tanks, and keeping them in perfect condition, is far more enjoyable on both an immediate basis and also a long-term one.
The trick is to design something fit for purpose if you have defined your needs.
For low maintenance a simple effective method is a settlement chamber. For example a 20,000L rain tank would handle 7 internal connected tanks. Even fine particles settle out with low (almost nil) flow. That's it for mechanical filtration!! Nothing to clean or check or change. No moving parts to break. Perhaps every few years you could flush the settlement tank clean. I installed bottom drains on mine but you could pump out too.
Auto water change is simple.