(06-08-2012, 03:09 PM)Fishbone Wrote: Of course the fish owners count It's just that it is a while different story with fish than with providing water for drinking. I had heard it was better to use treated trap water because it still had minerals, our at least some hardness could you use RO water and add some of the mineral salts for freshwater aquariums?
It is indeed better with tap water in most cases for fish keeping. RO water has 0 buffer due to there is no mineral in it. Fish don't really need those minerals, but if there is no mineral in the water = water hardness is totally soft with no buffer. Thus all fish keepers use RO water must add some kind of buffer products, or the PH can instantly crush as soon as there is even the slightest acidic element.
For my freshwater tropical fish, I will just stick with my tap water treated with Prime.