Ummm.. NO.
Yes some have a problem with keeping up good tank maitenance, HOWEVER, there is absolutly such a thing as over crowding, and doing so for any extended amount of time can - and most likely will result in not only physical abnormalities, but also pronounced health deficiencies. Having a "strong" filtering system is always advised for optimum health and pristine water parameters, but that in its self cannot be your "save-all" for an over crowding situation. If you simply enjoy and prefer a full tank (as most of us do), there are better ways to go about achieving that rather than having larger (or soon to be large) fish crammed together. For one, you can opt for smaller species in a larger tank and form colorfull schools of them, resulting in not only a varied stock, but also a treat for the eyes. Or if you insist on larger species, then go for a larger tank, get them while they are smaller so you can stock more, and have a back up plan for when they reach adult sizes, such as investing in more tanks, or knowing of, and communicating with (in ADVANCE) a zoo, aquarium, LFS, or what not about them adopting the animal. IMO though, you should never purchase something (no matter how tempting it may be) unless you are well educated on that particular animal, and are fully capable of caring for it through out the entirety of it's life. I don't have the time right now to go into detail as far as the damage that could ensue due to over crowding, however there are many threads that have covered this topic in the past, so I am sure you could find more info. through them. All I will say, is that it is a real problem, and if ignorant to it's issues (which you seem to be...... But please, I mean no offense by that), then you might be facing a potential disaster. I will go more into all of this later when I get the opportunity, as I am working right now, and have to go make my rounds. Anyways, if nothing more, I hope this will make you slow down a bit, and do some more research!! Keep us posted ok. Good luck.
-Em
