you wont need to do any dosing the coral rock and coral sand if you use it will keep it sweet as. id be inclined to put the coral rock in a bucket of water with some bleach for a day just to make sure theres no bad stuff left on it that can rot and rinse well (do a few 100% water changes in bucket) you wont need the reactors or carbon sell that stuff and use it to buy some sweet fish. i would look at peacocks electrric yellows theres heaps of options but it would pay to decide on what you want first then check on here for compatability issues before buying