Hi I have had fish for 25 yrs but need some salt water questions answered.I had a fish only sw tank back in the 80's and when I mixed the salt into the water I only used tap water.Tap ph is 7.3 med hardness.My question is if I am going to set up a nano reef how is the best way to mix the water.Do I need ro water and buffers?Are the Bio cubes I see at the lfs worth the price?Any help or pointers would be great.