I have my 30 gallon plant tank set up. All the plants are in & it is stocked with all the fish I want to put in it. ( guppies, platies, swords, tetras, angels) I got off to a bad start. My female sword just laid on the bottom when I put her in. It is over an hour & she is still there. The others appear fine. To prevent a disease taking over the tank, I have disposed of her. I hope I did the right thing. My question is, how important are water changes ? I have always done them on my other tanks, but I am afraid of disturbing the plants. What do you think ?