I realize this thread is older but wanted to add a bit:
Nearly everyone overfeeds. If you dump food in your tank and even
some of it is hitting the bottom (or floating around like crazy, getting sucked up into the filter, etc.) you are putting too much in IMO and IME. Try small amounts that are being eaten basically as soon as they hit the water. Try a bit more after that, and call it a feeding.
You can even limit feedings to every 2-3 days if you want. It is nearly impossible to "starve" a fish, but quite easy to overfeed them.
Whoever told you water changes are "too much" doesn't know their arse from their elbow.
It's impossible. You water cannot be
too diluted of waste products and
too replenished of trace elements and minerals. That's a hold-over from the thinking in the 1970's where every drop of old tank water was cherished and preserved.
It is, however, possible to change water and fail to match the temperature of the new water to the old water, causing stress. It is also possible to have a tank with so much waste that performing a large water change can actually be detrimental to the fish, which have slowly adjusted to poor water quality (high nitrate, etc.).
Those are both separate issues, not related to the water change itself.
People rasising angels and discus in the tropical hobby sometimes perform daily 70-90% water changes. They don't do this to increase their water bill. They do it to maintain the highest level of water quality and get the best growth and coloration from their fish.
Here's a few breeders who do just that:
http://angelfishgardens.com/page2.htmlhttp://aquafind.com/...ngAngelfish.phpAnd a similar thread:
http://www.monsterfi...p/t-294775.html
Edited by Gene2308, 11 April 2010 - 06:39 AM.