I'm wondering what would be a better choice to use for my new 55 gallon:. My tap water is from a well with very high nitrates; like 80ppm. I have a RO system here for our drinking water which is also softened (I'm not sure why) . I initially filled the tank and started my fishless cycle with the ro water, thinking that was the way to go. I also set up a holding tank so that I will always have enough of the ro water ready for pwc's. I've been doing some reading here and a few other sites about using ro water and the important minerals and such that i may be lacking now and I'm not really sure what I should do: use the ro water and add a supplement such as replenish, or use the well water with high nitrates and treat for the nitrates. Any advice would be great.. Thanks!