Can anyone recommend a freshwater buffer for me? I'm going to be using RO water for a new tank and would like to get the water to a pH of about 7.5. Can anyone recommend something affordable and reliable? I see several products that claim to do this but I've never had to deal with RO water before (other than for marine tanks). I may just use some of my raw water mixed with the RO to create a good mix. Maybe an easier route. Thoughts?