Water changes, the ever other week chore that most people hate!!
Many people ask how big of water changes I should do, well it depends on the size of your fish and whats in the tank.
In my 29G (that is fully stocked) I do a 30% water change every two weeks....I have went up to 4 weeks without doing a water change but the plants saved me (I wasn't lazy, I love water changes but I was gone)
now for big monster fish tanks (that are fully stocked)......60 percent water change every 2 weeks
for discus tanks that the main focus is discus I reccomend a 30 percent water change every week or a 60 percent water change every other.
GENERAL RULES: In a tank that is full of tiny fragile fish do smaller more frequent water changes.
In a tank that is fully stocked with bigger fish (rainbowfish, angels, rams) you can do less frequent bigger water changes.
why do I say this? cause the bigger fish can handle it and love it. While smaller tedious fish cant handle that big of a change and will sooner or later die in a water change.
in a fully planted tank with 2-3 inch fish you can get away with 30% chlorinated water changes (depending on your city parameters)
When it comes to shrimp however you need alot more closely watched water changes for taiwons and such with ro water and all that hoodad doodad.
When it comes down to it, water changes make almost everything better.
that's all I have to say about water changes for now.
__________________
Plants, wood, rocks, fish, dirt and water equal nature aquarium.