The problem is your opinion is not based on fact. Water changes are nessecary on ANY tank. Nitrates are not the only thing that builds up in the water. There are also a ton of hormones the fish release, one of which is a growth inhibiting hormone. You do more water changes that has almost not concentration in the water and doesn't effect the growth of the fish at all, that is why they grow larger and faster. I can feed fish in tanks that get WCs every day and ones in tanks that get them once a week the same amount of food, and the ones in the tank with the cleaner water will always grow faster. Africans aren't a species either by the way, its amazing how most of you malawi people can't distinguish between Malawi, Tanganyika, Victoria, West Africans and so on. Just because Discus are from south americans I don't call them South american cichlids, but thats another point about uneducated fish keepers. Your malawis are not hard fish to get to spawn, most malawis and their difficulty to spawn is almost as easy as convicts and jewels. Thats one of the reasons why you can get them for a couple dollars at your LFS. I have seen pH shock, and low O2 levels in tanks as well quite a few times, and EVERY time, and everyone I know that has had to deal with it, the fish go to the surface and gasp. Why do they do that, because they can attain a small amount of O2 from the air, they will not go to the bottom and gasp if there is a low O2 level, or pH flucuation in the tank.
Never need waterchanges in a planted tank huh? How sadly mistaken you are. First those hormones, still build up in planted tanks. Plants also utilize the minerals and other such things in the water and will exhaust that source. Water changes are in some ways more of a nessecity in planted tanks, because you need to keep the plants healthy as well. Fish don't sit in the same water for weeks on end in the wild, the water is turned over generally in a rather rapid pace, so frequent WCs in a tank are much better then infrequent ones.
I argue your points more often than others, and many other people's because what info you spew out there to people isn't generally correct information. There is a right and wrong way to keeping fish, by all rights what your saying is just because someone has managed to keep a goldfish in a 1gallon bowl and its doing ok, then I guess thats not keeping it the wrong way, kinda like its ok to keep a 10" oscar in a 10gal because he's been doing ok for a while. For as long as many people on here have been keeping fish, its really amazing how little some of you know about the basics of keeping them. I speak from expirience and the extensive knowledge I have about keeping freshwater fish. You can keep them for a long time, but that doesn't mean they are healthy or that they will live to their full life span.
But Hey, I'm just a rude, arrogant and most likely unknowledgable guy, so don't pay any attention to the information I give out.
