How many tanks did it take before you noticed that your house was either getting overrun by different fish tanks, or that you had a good problem and needed to possibly downsize?
I would say it was after the second tank, I realized that keeping fish is for sure a hobby but can overwhelm someone’s house easily. Each tank to me, really can be a different environment with totally different species housed within from around the world - it's basically like being able to see the wild or parts of the world in nature within your house, especially when you make the tank match their home environment with decorations, plants, woods or rocks, etc.
I remember with my mum, we used to have small fish tanks but the more fish we ended up getting the more tanks we got until we got a huge standing one. That was when my mum realized she had a problem with getting too many fish.
The big tank ended up cracking and that was when my mum gave up with keeping fish as we lost most of the fish when that happened.