DreamertK said:Depends on what kind of fish you have in the tank. Amano are not as hardy, but wont be hunted to extinction by bettas. While red cherries are very hardy and cheap, but an expensive snack!
I'm unsure why anybody would think water changes are stressful, to fishmitch70 said:I always do changes with lights off as I was told it was less stressful for the fish - but not sure if this is true or not