I'm confused why rehoming doesn't seem to be an option most agree with, why is this? Don't we all do this when we stock our tanks initially (to a certain extent)?
Good question that I don't think anyone has asked out loud (and before it's "too late") before.

I guess I'm not saying that overstocking and "rehoming" can't work, but no we do not all overstock our tanks and then have to give up the fish we buy and care for.
I guess I've always thought: Why do some people feel it's alright to do that?
If you or I don't want (e.g.) a fish that grows to be 12" long and lives 20 years, then why in the name of reason would we buy one? (Right?) So....for an example, when I buy a freshwater Oscar, I tend to have him until he dies at a ripe age of 22 years and 13 inches in length. To facilitate this, I do not buy five of them and cram them into a small tank, anticipating 30-100% attrition, whether by fighting or exile. In reality, my Oscar (singular) lived in a 75 gallon tank sparsely decorated with some driftwood along with a similarly sized and aged Pleco. As adults I fed them about weekly, did water changes rarely. It was a great tank and Oscar was a great fish!
Who could argue with that? And so I wonder why don't all aquarium stories go something more like that?With animals we tend to respect as pets like dogs (vs those we raise to eat or hunt), "rehoming" would be considered bad owner behavior without question. Right? To make a crazy example out of it: nobody fills up a room with puppies with the idea of giving the ones that "outgrow the room" to some stranger or selling them back to the store as soon as they grow up. In real life, the only time an owner usually gives up their dog is when the relationship has failed....usually due to the owner not really being either ready or equipped in the first place - for whatever reason - for what they were getting into.
I don't see the situation with our aquarium animals much differently. In fact, since most of our saltwater fish are still taken from the wild, you might argue there should be even more weight placed on our "ownership" of them vs domesticated animals which are both bred and farmed.
When possible, I generally take the more conservative route. The one that allows room for error, slack in routine, survival during power outages, etc. Overstocking a tank does not set you or the tank mates of the to-be-moved up for the best situation possible. Unfortunately, "s**t tends to happen" in that kind of scenario. You may get lucky - people do.

When you look at stocking a tank reasonably, I think it has to happen one of two ways. Either you start by setting the aquarium size and the stocking list has to fall in line with that, or you start with a stocking list and the tank has to be specified from that. Trying to have it both ways means a sacrifice somewhere there shouldn't be one, IMO.
I hope this helps!

-Matt

