Welcome! I believe your nitrites and ammonia reading should be zero before you stock with anything, this helps to ensure acclimation stress is reduced. The UGF will work fine for awhile, but I'll never forget what they looked like after a year in my planted tanks (full of brown crud) so that's why I'll recommend you take the tank down and remove this before you get it heavily stocked. Some alternatives are having access to the short PVC riser that gives you access to the absolute bottom of the tank (under the UGF) and sticking your siphon hose in there on a regular basis (to remove much of the crud/detritus) but it sure seems easier to just remove it before hand. Either way, it's a long-term quality issue and not short term. If you plan on keeping a few soft corals and some fish, I'd say dosing isn't expressly needed, as wchanges will suffice. If you are going to deck this out with many corals, I'd suggest using a two-part Ca++/Alk additive very common in most LFS> be sure and purchase the corresponding test kits to ensure dosing accuracy and only dose in the mornings, not in the evenings because your tank's pH will be the highest at this point making the chemical balances during your dosings more critical (increased chance of precipitation and lowering of your desired parameters) and could increase shock to your system especially when adding the pH-raising alkalinity components.
HTH
BM
