There are many good ro systems that can be purchased on ebay and amazon for around 150 dollars... 3 , 4, and 5 stage that can get your water tds down to zero ppm ... easy to hook up to any water tap and for normal use the membranes last about a year before needing replacement. For many of the tetras and soft water fish breeding success becomes easier in my opinion using 2/3 ro water mixed with about 1/3 city of edm water... or just pure ro water to spawn the fish then doing the mix to raise the fry as they need many of the minerals that
exist in untreated water for their normal growth.