Everyone has their way of doing things. That being said I'll throw my 2 pennies in there.. The main 3, DKH CALCIUM AND MAG are the building blocks of your tank. So picture NITRATE AND PHOSPHATE and the fuel that keeps the egine running. Having a nano with the need to do consistent water changes simply because of the size the bulding blocks should come with the water changes. Lets say the system is a 5 gallon nano, a weekly 2.5 gallon water change is the goal.. but what fails to develop doing that kind of maintenance is the nitrate and phosphate. Neo phos at roughly .5 - 1 ml a day depending on the number of corals should keep the zoas happy and nitrate I have found B-ionic nitrate to work very well... again depending on how many inhabitants you have i would do .5 - 1ml a day and test daily for a week or 2 to make sure its not excessive and adjust accordingly. I sell many of my fragged Zoa's that i can literally put 3 on a 2in tile and its covered completely inside 3 weeks and ready to frag. This is a few from the last batch Im growing out.